Check Description *after* %-expansion (want values not %exp token names)

For .info example:

  Description: PostgreSQL database adapter for Python %type_raw[python]
  Type: python (2.4 2.5)

Description is literally 57 chars in .info but only 42 chars for any
actual variant, and that latter is what matters

Closes https://github.com/fink/fink/issues/82
nee https://sourceforge.net/p/fink/bugs/1389/
Patched to avoid locking issues on 10.9, as per discussion on -devel:

http://thread.gmane.org/gmane.os.macosx.fink.devel/21875
Oops.  Sync with distribution
Update Patchfile-MD5 to match new dpkg.patch
Sync with distro again
Fix Description field-length (<= 45 char) in SplitOffs (per new validator test)
Fix perl interp path for perlversions other than system-perl

Undoing part of 4d5f81aafd68d6e9542168e2b622eaf026669f8c which assumed
that the perl interpretter for X.Y.Z is *always* perlX.Y rather than
perlX.Y.Z. That's only true for system-perl, which is only one
specific (but different per kernel) variant on each OS X. Fink
supplies other interp versions, and uses the fully-versioned
interpretter name.