Fix typos in spawn() documentation.

Author: chriskohlhoff

asio/include/asio/spawn.hpp

@@ -130,7 +130,7 @@ class basic_yield_context
 };
 
 #if defined(GENERATING_DOCUMENTATION)
-/// Context object the represents the currently executing coroutine.
+/// Context object that represents the currently executing coroutine.
 typedef basic_yield_context<unspecified> yield_context;
 #else // defined(GENERATING_DOCUMENTATION)
 typedef basic_yield_context<
@@ -217,7 +217,7 @@ void spawn(basic_yield_context<Handler> ctx,
     const boost::coroutines::attributes& attributes
       = boost::coroutines::attributes());
 
-/// Start a new stackful coroutine that executes in the contex of a strand.
+/// Start a new stackful coroutine that executes in the context of a strand.
 /**
  * This function is used to launch a new coroutine.
  *

asio/src/doc/reference.qbk

@@ -88739,7 +88739,7 @@ This function is used to launch a new coroutine.
 [section:overload3 spawn (3 of 4 overloads)]
 
 
-Start a new stackful coroutine that executes in the contex of a strand. 
+Start a new stackful coroutine that executes in the context of a strand. 
 
 
   template<
@@ -106138,7 +106138,7 @@ The number of bytes written. If an error occurs, returns the total number of byt
 [section:yield_context yield_context]
 
 [indexterm1 yield_context] 
-Context object the represents the currently executing coroutine. 
+Context object that represents the currently executing coroutine. 
 
 
   typedef basic_yield_context< unspecified > yield_context;