0027176: Configuration, CMake - INSTALL_DIR is a common prefix for all other install...

0027176: Configuration, CMake - INSTALL_DIR is a common prefix for all other install variables

Possibility to customize layout of installation of OCCT is introduced by:
- variable INSTALL_DIR_LAYOUT - select one of the two predefined layouts: either Windows (classic OCCT layout) or Unix (Linux standard)
- variables INSTALL_DIR_* (BIN, LIB, INCLUDE, RESOURCE, DOC, TESTS, SCRIPT, SAMPLES, DATA) - specify locations of relevant components
- variable INSTALL_DIR_WITH_VERSION (bool) - specifies whether full version of OCCT should be used in paths in Unix layout

Files LICENSE_LGPL_21.txt and OCCT_LGPL_EXCEPTION.txt are always installed.

Environment is extended to support non-default layouts.
For that, environment variables "CSF_OCCT*Path" are defined, corresponding to CMake variables INSTALL_DIR_* described above.
Visual Studio environment, DRAW, tests, samples are amended to use these variables instead of (or as alternative to) CASROOT.

Settings of Products-specific vars are removed from environment scripts.

File genconf.bat was corrected to avoid error message for the case when path to TCL contains spaces.

Product name in rc files changed to "Open CASCADE Technology".