Add Sql formatter

This first version of the sql formatter is taken from dbeaver project.

it is configurable using closure

```
sql {
   sqlFormatter().configFile // the configuration file
}
```

configuration file support following properties (with default values)

```
sql.formatter.keyword.case=UPPER
sql.formatter.statement.delimiter=;
sql.formatter.indent.type=space
sql.formatter.indent.size=4
```

Author: baptistemesta

lib/src/main/java/com/diffplug/spotless/sql/DBPKeywordType.java

@@ -0,0 +1,27 @@
+/*
+ * Copyright 2016 DiffPlug
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.diffplug.spotless.sql;
+
+/**
+ * Forked from
+ * DBeaver - Universal Database Manager
+ * Copyright (C) 2010-2017 Serge Rider (serge@jkiss.org)
+ *
+* Database keyword type
+*/
+public enum DBPKeywordType {
+	KEYWORD, FUNCTION, TYPE, OTHER
+}

lib/src/main/java/com/diffplug/spotless/sql/FormatterToken.java

@@ -0,0 +1,67 @@
+/*
+ * Copyright 2016 DiffPlug
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.diffplug.spotless.sql;
+
+class FormatterToken {
+
+	private TokenType fType;
+	private String fString;
+	private int fPos = -1;
+
+	public FormatterToken(final TokenType argType, final String argString, final int argPos) {
+		fType = argType;
+		fString = argString;
+		fPos = argPos;
+	}
+
+	public FormatterToken(final TokenType argType, final String argString) {
+		this(argType, argString, -1);
+	}
+
+	public void setType(final TokenType argType) {
+		fType = argType;
+	}
+
+	public TokenType getType() {
+		return fType;
+	}
+
+	public void setString(final String argString) {
+		fString = argString;
+	}
+
+	public String getString() {
+		return fString;
+	}
+
+	public void setPos(final int argPos) {
+		fPos = argPos;
+	}
+
+	public int getPos() {
+		return fPos;
+	}
+
+	public String toString() {
+		final StringBuilder buf = new StringBuilder();
+		buf.append(getClass().getName());
+		buf.append("type=").append(fType);
+		buf.append(",string=").append(fString);
+		buf.append(",pos=").append(fPos);
+		buf.append("]");
+		return buf.toString();
+	}
+}

lib/src/main/java/com/diffplug/spotless/sql/KeywordCase.java

@@ -0,0 +1,26 @@
+package com.diffplug.spotless.sql;
+
+import java.util.Locale;
+
+/**
+ * @author Baptiste Mesta.
+ */
+public enum KeywordCase {
+    UPPER {
+        public String transform(String value) {
+            return value.toUpperCase(Locale.ENGLISH);
+        }
+    },
+    LOWER {
+        public String transform(String value) {
+            return value.toLowerCase(Locale.ENGLISH);
+        }
+    },
+    ORIGINAL {
+        public String transform(String value) {
+            return value;
+        }
+    };
+
+    public abstract String transform(String value);
+}

lib/src/main/java/com/diffplug/spotless/sql/Pair.java

@@ -0,0 +1,50 @@
+/*
+ * Copyright 2016 DiffPlug
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.diffplug.spotless.sql;
+
+/**
+ * Pair
+ */
+public class Pair<T1, T2> {
+	private T1 first;
+	private T2 second;
+
+	public Pair(T1 first, T2 second) {
+		this.first = first;
+		this.second = second;
+	}
+
+	public T1 getFirst() {
+		return first;
+	}
+
+	public void setFirst(T1 first) {
+		this.first = first;
+	}
+
+	public T2 getSecond() {
+		return second;
+	}
+
+	public void setSecond(T2 second) {
+		this.second = second;
+	}
+
+	@Override
+	public String toString() {
+		return first + "=" + second;
+	}
+}