FindACE: Use CMAKE_TRY_COMPILE_CONFIGURATION instead of CMAKE_REQUIRED_DEFINITIONS
[Cleanup]
Set cmake options before executing system checks
FindACE: Allow to set minimum version also when not using pkg-config
[Cleanup] Fix typo in comment
Forbid CMake 2.8.11

CMake 2.8.11 fails on some systems with a very obscure error.
This is due to a bug when quoting libraries in try_compile, and it was
fixed in 2.8.11.1. Older versions do not seem to be this problem.
In order to ensure that the user do not use the bugged version (and
consequently complain about not being able to build the project) we
ensure here that the version is different from 2.8.11 and print a
readable error that the user will be able to understand.

See also: http://cmake.org/gitweb?p=cmake.git;a=commit;h=e65ef08bf2719ffd1cc4226f9594ff7127ad8b5e
Fix YarpCheckStructHasMember not being able to link ACE

On windows, checks using YarpCheckStructHasMember fail because the
symbol ace_main_i(int argc, char **argv) cannot be found.
For some reason this is defined only if you define main as
main(int argc, char **argv)
Do not overwrite user set CMAKE_DEBUG_POSTFIX variable
Revert "Explicitly define __ACE_INLINE__ if required in ace checks"

This reverts commit 2164abbee547b12269cdb9a02c21557dc2b88035.

This is not necessary when using CMAKE_TRY_COMPILE_CONFIGURATION