Add CDLaTeX recipe

Resolves milkypostman/melpa#1820
Merge pull request #1849 from alexeyr/cdlatex

Add CDLaTeX recipe
Refresh package contents when starting sandbox (see #1828)
Merge remote-tracking branch 'upstream/master'
Explicitly add GNU ELPA to sandbox makefile target (see #1828)
Merge pull request #1850 from dieterdeyke/master

fossil 1.21 uses _FOSSIL_ instead of the newer fslckout to store local data
Merge remote-tracking branch 'upstream/master'