Hefty update to the tex tool.

Hefty update to the tex tool.
It now iterates until all the warnings are gone and the auxiliary files
stop changing or it hits the max retires limit.

It adds the common auxiliary files to the emitter as sideeffects

Added support for glossaries, nomenclatures, lists of figures,
lists of tables, hyperref, and beamer

The user can entry environment changes like env['TEXINPUTS'] and
they get copied to env['ENV']['TEXINPUTS'] (thanks to  Dmitry Mikhin )

It also works with variantdir, duplicate =0

git-svn-id: http://scons.tigris.org/svn/scons/trunk@3435 fdb21ef1-2011-0410-befe-b5e4ea1792b1