Ensure gcc44 used on DragonFly unless specified otherwise

In the absence of a defined DRAGONFLY_CCVER, dports will use gcc44 to
build ports unless USE_GCC > 4.4 or USE_GCC isn't specified.

This is to prevent surprises when DragonFly is changed to gcc 4.7 by
default.
merge script: Support REMOVE file
merge: Add proper support for LOCK category

We need to populate a locked entry if the target directory is empty.
Get the files from DELTA.
Success: astro/cfitsio v3.310
Success: lang/f77 v0.3
Success: astro/p5-Astro-FITS-CFITSIO v1.09
Success: biology/mopac v7.1.11_1,1
Success: math/blocksolve95 v3.0_10
Success: astro/p5-Astro-Catalog v4.2.4
Success: cad/tochnog v20010211_6
Failure: science/libghemical v2.99.1_3
Success: astro/kstars v4.8.4