OS X: Improvements for getting install name of dylib.

In the case of a multi-arch dylib where none of the architectures
is the host architecture, otool -D returned multiple install names.
Genex: Fix indentation in docs.
cmSystemTools: Fix typo in comment.
Style: Don't put an else after a return.
Eclipse: fix #14204 and #14205: no file links to directories

If a source file name is empty, or if it is a directory,
don't create a linked resource to it.

Alex
enable_language: Clarify documentation

Describe explicitly the scope in which enable_language must be
invoked to handle all direct and indirect uses of a language.

While at it, re-word documentation of the OPTIONAL keyword to
avoid confusion over its partial implementation.
Don't run the WarnUnusedCliUnused test on Windows.

Even with the NMake Makefiles generator, it is not able to properly
clean up after the test.

 http://open.cdash.org/testDetails.php?test=193424220&build=2934501

 Internal cmake changing into directory: C:/Dashboards/My Tests/CMake-nmake10-x64-continuous/Tests/WarnUnusedCliUnused
 Error: cmake execution failed
 CMake Error: Error: generator : NMake Makefiles
 Does not match the generator used previously: Visual Studio 10
 Either remove the CMakeCache.txt file or choose a different binary directory.
cmCryptoHash: Increase alignment of HashFile buffer

The SHA512_Update implementation accesses input data via 64-bit
integers.  This requires alignment of the input buffer on some
architectures.  Align our stack-allocated buffer for file content to
satisfy this requirement.
CMake Nightly Date Stamp
Do not set CMAKE_MATCH_ variables when not neeeded

Each call to AddDefinition has overhead for variable watches and such.
Avoid extra calls when not needed.

This decreases the configure time for ParaView by 10 seconds on my
machine.  Without the change about 1,000,000 set-to-empty calls were
being made.  After the change it drops to about 100,000.
asm support: adapt to changes in CMakeDetectCompiler in 2.8.10

This fixes #14210. In 2.8.10 CMakeDetermineCompiler.cmake was
modified (or added), and now the _INIT variable must not
be set to a list anymore, before it worked.

Alex
Merge topic 'rpath-on-mac'

ff01f8b OS X: Improvements for getting install name of dylib.
Merge topic 'remove_extra_matches'

dc03499 Do not set CMAKE_MATCH_ variables when not neeeded
Merge topic 'minor-cleanup'

e3b7eac Style: Don't put an else after a return.
ad304a2 cmSystemTools: Fix typo in comment.
08319e0 Genex: Fix indentation in docs.
Merge topic 'suppress-unused-cli-with-value-in-cache'

6a6cda5 Don't run the WarnUnusedCliUnused test on Windows.
Merge topic 'FixAsmSupport'

bc460ea asm support: adapt to changes in CMakeDetectCompiler in 2.8.10
Merge topic 'FixEclipseCorruptProjects'

22f7934 Eclipse: fix #14204 and #14205: no file links to directories
Merge topic 'sha2-alignment'

75994d9 cmCryptoHash: Increase alignment of HashFile buffer
Merge topic 'doc-enable_language-scope'

b3b57e7 enable_language: Clarify documentation