Fixed subheading syntax.
Refreshed 'installation' section (copied from README).
Removed duplication of Param's doc (website).
Tried to make visiting Param's website more enticing.

Maybe I've cut out too much just to avoid duplication...
Cleaned up and expanded docstrings and comments
Added statement of public domain license
Added link to version.py file location to establish provenance
Changed example to be independent of param
Added to 'copyright' years (changes were made in the added years).
Adds method param_keywords to ParamOverrides which returns all keywords except of extra keywords
Adds parameter is_instance for ClassSelector which allows to actually select a class and not only instances of a class
Python 2.6 compatibility for param_keywords()
Moved numbergen from imagen to param
Added version module to release notes.
Moved numbergen from imagen to param
Merge branch 'master' of github.com:ioam/param
Updated Sphinx docs building system
Fixed sys.path issues in Sphinx conf.py
Updated release date.
Small clarifications to docs