Add parsing of text/calendar

parsed calendar data goes into the alternatives field
Removed commented code, and fix charset duplication
Revert change from binary to utf-8
Merge pull request #83 from stovenator/master

Handle text/calendar alternatives
Bumped version to 0.4.2
Improve header parser to not split quoted strings

Fixes a bug where an attachment filename has a semicolon in it
Merge pull request #84 from deepwell/attachment-with-semicolons

Improve header parser to not split quoted strings
Bumped version 0.4.3
Merge remote-tracking branch 'andris9/master' into partid_dev

Conflicts:
	lib/mailparser.js