Update package dependencies and build rules

- Added `cmake_modules` ros package to fulfil Eigen, etc.
- Added cmake find_package rule for GL, X11, etc
- Added toolchain choice if block for MacOSX and some specific CC and
CXX compiler flags
Update sources for platform dependent functions

Update sources for platform dependent functions:

- mostly fixes for MacOSX build
- replaced `std::chrono::monotonic_clock` with
`std::chrono::steady_clock`