YCMEPHelper: Add a warning if component name is "build"

This is commonly used as the build directory, and therefore code might
be deleted.
YCMEPHelper: Allow to set commands for "documentation" components
ExtractVersion: Fix bug with REVERSE_NAME
YCMEPHelper: Set some useful global properties
YCMEPHelper: Add function YCM_WRITE_CDASH_PROJECT_FILE

This function writes a Project.xml file that can be read and
interpreted by CDash.
YCMEPHelper: Add function YCM_WRITE_CTEST_SUBPROJECT_CONFIG_FILE

This function writes a cmake file that can be used in ctest scripts.
YCMEPHelper: Add function YCM_WRITE_DOT_FILE

This function writes a dot file that produces a graph showing all the
subprojects, dependencies and components.
BuildGazeboYARPPlugins: Add system dependencies to DEPENDS
Merge branch 'cdash_integration'
Add comment
InstallBasicPackageFiles: Improve documentation
FindOrBuildPackage: Add documentation
YCMEPHelper: Start adding documentation
Convert build and find modules documentation to rst
Start adding documentation

In order to make it easier to contribute modules and patches upstream,
use Sphinx like CMake does.

CC-Issue #46