Catkin build updates, some additions for MacOSX build

I tried to make as less intrusion in code as possible (at least no changes in algorithm code), however CMake rules have a lot of changes to make build possible.

Updated package dependencies and build rules:

- Added `cmake_modules` ros package to fulfill `Eigen` dependency, etc.
- Added cmake `find_package` rule for GL, X11, etc. Hence removed hardcoded library names/paths. 
- Added toolchain choice if block for MacOSX and some specific CC and CXX compiler flags

Update sources for platform dependent functions:

- mostly fixes for MacOSX build (`__exp10`, `isnanf`)
- replaced `std::chrono::monotonic_clock` with `std::chrono::steady_clock`

Add notes on catkin build:

Main difference seems to be `ros-indigo-cmake-modules` dependency. For MacOSX build is still not possible, due to clang C++ features coverage and gcc-clang incompatibilities (gcc build code but fails to link to libs built by clang, e.g. roslib, opencv). And it will still need a long howto about ros/brew/mac.