Parse the description format

[maxadamski]

Currently, nothing is done with the description field in Synset and LexicalUnit. Information about the description format comes in PlWordNets readme.

Parsing should be done lazily to avoid slowing down the initial loading of PlWordNet into memory.

Example description:

##K: og. ##D: owoc (wielopestkowiec) jabłoni. [##P: Jabłka są kształtem zbliżone do kuli, z zagłębieniem na szczycie, z którego wystaje ogonek.] {##L: http://pl.wikipedia.org/wiki/Jab%C5%82ko}

Desired behavior:

A new (memoized) method rich_description returns the following dict:

dict(
  qualifier='og.',
  definition='owoc (wielopestkowiec) jabłoni.',
  examples=['Jabłka są kształtem zbliżone do kuli, z zagłębieniem na szczycie, z którego wystaje ogonek'],
  sources=['http://pl.wikipedia.org/wiki/Jab%C5%82ko'])

[maxadamski]

Mostly done.

Sentiment annotations in descriptions (##A1, ##A2) and multi-word lexical units (<##DD>, <##s>, ...) still need some work.

There are many descriptions that do not conform to the described format. Should something be done about them? Currently, if parsing LU description returned an error, I try parsing Synset definition or description, and if this succeeds (it does most of the time), the LU description is not counted as malformed.