Fix project command documentation typo (#13384)

Commit 9090572f (Add ability to include a file in a project via a cache
variable, 2012-02-17) taught the project() command to check variable
"CMAKE_PROJECT_<projectName>_INCLUDE" but the documentation included an
extra "_FILE" by accident.  Remove it.
CTestUpdateSVN: Do not create repo directory first (#13349)

If the directory already exists some svnadmin versions report

 svnadmin: E200011: Repository creation failed
 svnadmin: E200011: Could not create top-level directory
 svnadmin: E200011: '.../CTest UpdateSVN/repo' exists and is non-empty
DeployQt4: workaround bug 13258 where ARGV1 is leaked into a sub function.
Tests/CustomCommand: Do not use 'main' in a library

Otherwise when linking 'CustomCommand' some linkers report

 ld: 0711-224 WARNING: Duplicate symbol: .main

Suggested-by: Daniel R. Gomez <gomez@teragram.com>
AIX-GNU: Link shared libs with -brtl,-bnoipath (#13352)

We already use these flags with the XL toolchain.  Use them for GNU too.
Ninja: also write link libraries to rsp file

and enable rspfile support on Linux, needed for commands longer than e.g. 2096152 characters on Ubuntu.
Ninja: remove some unused default arguments
Ninja: error on missing rspfile_content
include: Ignore empty string as file name (#13388)

Previously CMake silently accepted the empty string and added a bogus
dependency on the current directory.  Instead warn about the empty file
name and ignore it.  We cannot make this an error because there may be
existing projects that accidentally depend on the old behavior.

Add a RunCMake.include test to cover this case.
Add ASM platform information for GNU compiler on AIX (#13390)

Among other flags this sets RPATH flags correctly so that CMake knows
how to treat CMAKE_PLATFORM_REQUIRED_RUNTIME_PATH for the ASM language.
This is the GNU compiler equivalent to commit a0bab7ae (Add ASM platform
information for XL compiler on AIX, 2011-03-02), made for XL.
Ninja: disable work around when linking with mingw

The work around is only needed by older GCCs (only testet 4.4/4.7)
Ninja is very new so chances are high that there is also a new mingw.

Use slashes in link rsp file, because ar.exe can't handle \.
Ninja: enable response file support on Mac (length 262144)
Ninja: sysconf() is declared in unistd.h
if: Document that macro arguments are not variables (#13393)

A common mistake is to write

 macro(foo arg)
   if(arg)
   endif()
 endmacro()

and expect if() to treat "arg" as a variable.  The documentation of the
macro() command already states that arguments are not variables, but
users writing the if() command may not look at the macro() docs.
Add a note to the if() documentation.
install: Fix COMPONENT option

Since commit 7ced0732 (make default install component name configurable,
2012-05-13) the COMPONENT option has not worked in all cases.  The
change restored use of the broken SetDefaultString previously removed by
commit 43cad3e4 (fix the default "Unspecified" component, 2008-03-26).

Remove SetDefaultString and use the default component name only when an
invocation does not specify a non-empty COMPONENT option value.

Bug-Debian: http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=680825
Merge topic 'inject_code_via_variable'

280a333 Fix project command documentation typo (#13384)
Merge topic 'fix-CTestUpdateSVN-svn1.7'

c785c6b CTestUpdateSVN: Do not create repo directory first (#13349)
Merge topic 'deploy-qt4-workaround-bug-13258'

374b9b9 DeployQt4: workaround bug 13258 where ARGV1 is leaked into a sub function.
Merge topic 'fix-CustomCommand-main'

d54618f Tests/CustomCommand: Do not use 'main' in a library
Merge topic 'aix-GNU-shared-libs'

767a7ad AIX-GNU: Link shared libs with -brtl,-bnoipath (#13352)