yarp-config now handles context and robot files.
Moving diff-patch library to extern directory [thanks paulfitz]
[ffmpeg] add header files suggested by @lschilli, closes #71
Merge pull request #86 from elen4/rfAPI

adding methods to ResourceFinder to retrieve locations for writing data
Mark yarp::os::ResourceFinder::getContextPath() as deprecated
Merge pull request #78 from elen4/yarpconfig

yarp-config handling context and robot files
Use GNUInstallDirs variables for install destination

Since we depend on CMake 2.8.7 we can do it (it's included in CMake
since 2.8.5)

The main effect is that on Debian/Ubuntu, libraries will be installed
in lib/${arch}/ instead of in lib, enabling installation for
multi-architecture (see http://wiki.debian.org/Multiarch)

Also it makes no longer necessary to remember to use lib${LIB_SUFFIX}
to install in the correct lib dir since it is handled automatically.
Merge pull request #89 from drdanz/GNUInstallDirs

Use GNUInstallDirs variables for install destination
Fixing yarp-config compilation on Windows and string-related inconsistencies
Removing spurious line from commit 070c2a6eb688547b3bdc4dd2c6feb78c5f34be2a
Link pthread as private

This fixes the CMP0023 warning with cmake 2.8.12
Disabled warnings when compiling 'diff' library on Windows