Add FindBacktrace.cmake module.

It designed to search for implementation of backtrace(3) routine.
Currently it is used in OpenBSD Ports for building Clementine
music player.

A lot of input from brad.king@ and neundorf@.
FindLATEX: Find ps2pdf with MikTeX.
CFBundle test: Add isysroot argument when calling Rez.
Genex: Add a test for the LINK_ONLY expression.

Commit 239b0c6b (Don't add invalid content to static lib
INTERFACE_LINK_LIBRARIES., 2013-10-20) extended a test which
excercised the logic of the LINK_ONLY generator expression.

Commit ef10b87c (CMP0022: Plain target_link_libraries must populate
link interface, 2013-11-02) removed the instance of LINK_ONLY which
was excercised by that test.

Add a new test which excercises the other instance of LINK_ONLY by
setting the CMP0022 policy to NEW and consuming the contents of the
INTERFACE_LINK_LIBRARIES target property.
CMake Nightly Date Stamp
Disallow invalid target names (#13140)

Exclude Borland and NMake from the CMP0037 test. They do not accept
the colon in a target name.
Disallow link-to-self (#13947).
Disallow linking to utility targets (#13902).
cmGlobalGenerator: Rename the FinalizeCompileDefinitions method.

This will soon also finalize include directories.
cmTarget: Don't finalize include directories in GetIncludeDirectories.

Rely on that having been done by the cmGlobalGenerator.
Merge topic 'cfbundle-test-no-cl-tools'

a5aadcd CFBundle test: Add isysroot argument when calling Rez.
Help: Format execute_process command documentation

Use a code-block for the signature.  Format the options as a definition
list.
Help: Clarify execute_process COMMAND argument behavior

State in the execute_process how COMMAND arguments are passed to
the child.  Add a note at the end about how the command differs
from add_custom_*().

Suggested-by: Alan W. Irwin
CMake Nightly Date Stamp
Help: Add cmake-language.7 manual
Help: Reference cmake-language.7 comment docs from cmake-developer.7

The cmake-language.7 manual now documents comment syntax.  Reference it
from cmake-developer.7 when discussing how to add comment-enclosed
documentation to modules.
cmExportSetMap: Override clear() to delete held resources

Replace the std::map<>::clear() method with one that first deletes
the cmExportSet instances held by each map entry, and then clears.
Otherwise the cmGlobalGenerator::ClearGeneratorMembers added by
commit 5cf1120f (cmGlobalGenerator: Refactor member cleanup between
configures, 2013-11-04) leaks the cmExportSet instances.
Merge topic 'doc-execute_process'

3bb6266 Help: Clarify execute_process COMMAND argument behavior
ea6b656 Help: Format execute_process command documentation
Merge topic 'doc-cmake-language'

79fd233 Help: Reference cmake-language.7 comment docs from cmake-developer.7
a931ee4 Help: Add cmake-language.7 manual
Merge topic 'tll-target-policies'

596b2a8 Disallow linking to utility targets (#13902).
301bb5c Disallow link-to-self (#13947).
05f5fde Disallow invalid target names (#13140)