documentation: Paragraphs on epicsEvent and Cygwin support.

documentation/RELEASE_NOTES.html

@@ -13,6 +13,23 @@
 <h2 align="center">Changes between 3.14.11 and 3.14.12</h2>
 <!-- Insert new items immediately below here ... -->
 
+<h4>Support for Cygwin 1.7</h4>
+
+<p>Base can now built with shared libraries on Cygwin 1.7.x, although only with
+the gcc-3 compiler.  Cygwin 1.5.x only works when compiled without shared
+libraries (set <tt>STATIC_BUILD=YES</tt> and <tt>SHARED_LIBRARIES=NO</tt> in
+<tt>configure/CONFIG_SITE</tt>).  There is code in Base now that depends on the
+Cygwin version, so make sure that you rebuild Base if you upgrade your Cygwin
+installation.</p>
+
+<h4>epicsEvent</h4>
+
+<p>epicsEvent is now explicitly required to act as a simple binary semaphore.
+A single epicsEventSignal call must awaken just one thread when multiple
+threads are waiting for the event.  A test thats checks for this has been
+added to epicsEventTest and the application developers guide is being updated
+to describe this requirement.</p>
+
 <h4>Enable array puts to subArray records</h4>
 
 <p>It is now possible to put an array into the VAL field of a soft channel
@@ -25,7 +42,8 @@ NELM=MALM and read one element out of the VAL field each time).</p>
 
 <p>64-bit binaries for Microsoft Windows platforms can now be built using the
 target architecture windows-x64, which is also a valid cross-build target for a
-win32-x86 host.  We do not currently support 64-bit MinGW or Cygwin builds.</p>
+win32-x86 host.  We do not currently support or recommend trying to use 64-bit
+builds on MinGW or Cygwin.</p>
 
 <h4>Deleted osf-alpha targets</h4>