pywrap: Remove silence_swig_warnings.mk

Different swig versions vs compiler versions generate different
warnings. There is no point in silencing just one of them.

And swig authors seems to be good enough in fixing these, just make sure
to update to new enough swig and this shouldn't be a problem.

Signed-off-by: Cyril Hrubis <metan@ucw.cz>
templates: Fix description block id, add description

The description block id is descr not description

Add description block where it's missing

Signed-off-by: Cyril Hrubis <metan@ucw.cz>
pylib: Add custom comment filter and use it descr

Add custom comment filter that adds ' *' to each line of the input.

Make use of the filter to convert descr block into nice C comment.

Signed-off-by: Cyril Hrubis <metan@ucw.cz>