Packaging: Add policy for development modules (python, perl etc)

[TraceyC77]

Summary from ermo

For packages such as python modules or perl modules, the accepted practice is have them be normal packages with no -devel component. In the cases where these modules would be split by the default ypkg policy (for instance because they contain category 3 man pages like in a recent package update), the current best practice is to add a patterns : /* stanza to keep everything in the main component for convenience.

For interested parties, the ypkg default behaviour in the presence of category 3 man pages was updated in this commit: https://github.com/getsolus/ypkg/commit/c47d587173b1217f9c6c7a2170cb03a04af84ad8

The justification for this default policy setting relates to how man pages are organised cf. man man:

DESCRIPTION
(...)
      The table below shows the section numbers of the manual followed by the types of pages they contain.

       1   Executable programs or shell commands
       2   System calls (functions provided by the kernel)
       3   Library calls (functions within program libraries)
       4   Special files (usually found in /dev)
       5   File formats and conventions, e.g. /etc/passwd
       6   Games
       7   Miscellaneous (including macro packages and conventions), e.g. man(7), groff(7), man-pages(7)
       8   System administration commands (usually only for root)
       9   Kernel routines [Non standard]