add back the build part, that was in .gitignore

Signed-off-by: Pierre Tardy <pierre.tardy@intel.com>
fix color for step mouseover popup

Signed-off-by: Pierre Tardy <pierre.tardy@intel.com>
update manual/introduction to follow one-sentence-per-line policy
update manual/installation
update manual/cfg-builders
update manual/cfg-buildfactories
update manual/cfg-buildslaves
update manual/cfg-buildsteps
update manual/cfg-global
update manual/cfg-interlocks
update manual/cfg-intro
update manual/cfg-properties
update manual/cfg-schedulers
update manual/cfg-statustargets
update manual/cfg-www
update manual/cmdline
update manual/concepts
update manual/configuration
update manual/customization
update manual/optimization