Install documentation update

Pacman section updated to reflect the obsoleted status
OSG Client references and install section updated
manage-glidein description reformatted to be more similar to the rest of the documentation
Updated documentation, consistency, links, general updates

- Name is GlideinWMS
- Uniform component names (User Pool, WMS Pool, ...)
- HTCondor instead of Condor
- updated links to condor manual
- no more dead links
- more links to RPM installs
- Pacman no more available
- removed GCB section
- kept quill but did not check its validity/did not update

remaining TODO:
Is is there plan for a tarball installation of OSG Client via installer?

documentation.html:
Paper list in the documentation list.
Suggest an article for references to GlideinWMS

upgrade.html
Replace CVS with GIT commands?

pool_install.html:
does the “condor” command exists?
/path/to/condor/location/condor start
/path/to/condor/location/condor stop
replaced cvs command with git pull origin branch
applied suggestions from Parag review
Merge branch master_marco_doc into branch_v3_2