Improve parsing: make the parser recognize synonyms

[elze]

Make the parser recognize that some skill keywords are synonyms of others: e.g. SVN is the same as Subversion, MSSQL is the same as SQL Server.

So far we have identified these synonyms. We can create a Python dict object -- a synonyms dictionary -- in the parser, and for each skill keyword (primary or secondary) we can check whether it is a key in this dictionary:

MS SQL -> SQL Server
MSSQL -> SQL Server
NodeJS -> Node
RESTful -> REST
SVN -> Subversion
TFS -> Team Foundation Server

(Similarly to NodeJS, we should look for alternative spellings of other Javascript framework names: e.g. AngularJS -> Angular, etc.)

[elze]

Added a lot of synonyms, and made the parsing script recognize them. But as we continue to add new skills, we will have to continue adding new synonyms.