Initial commit of cmake updates.

- Separates main config from library.
- Adds detection of boost and OCE, falls back to user supplied paths or internal
  boost headers.
- Upps minimum cmake requiered to 2.8.
- Implements use of GNUInstallDirs module to properly install libraries on
  multilib systems.
- Documentation can be built with "make doc", does not currently install.
- Add option MONOLITHIC_BUILD to make one SMESH library, disable to get original
  library set.
- Remove SMESH_ prefixes variables for built type and install prefix in favor
  of default cmake ones.
Fixed compilation issues on OSX
Removed SMESH_INSTALL_PREFIX
Removed manual oce paths settings in the Travis build bash script
Merge pull request #6 from tpaviot/review/cmake

Review/cmake