Update revision.txt

Author: Federico Fissore

build/shared/revisions.txt

@@ -9,6 +9,9 @@ ARDUINO 1.6.4
 * Warning levels can be set in File > Preferences
 * When compilation fails, editor highlights the reported row
 * Windows and MacOSX: updated bunbled JVM to 1.8.0_45 (latest available atm)
+* Disabled "uncertified" warning (requires avr core >= 1.6.6, sam core >= 1.6.4)
+* Additional boards/cores can be listed specifying comma separated list of package_SOMETHING_index.json url in File > Preferences
+* MacOSX: fixed wrong sketch opened when double clicking on a .ino file
 
 [libraries]
 * Bridge fixes