Parse Selectors: don't add '*' to list of pseudo elements
Compile Properties / Values: two bugfixes

- change return value for a tag which can be added to the 'to_set' array to
  False (as None is a valid value)
- extra handling for value None, produced slightly incorrect value for
  'tag_value' tags: current.tags->null
  this evaluates to null, but is quite redundant
Merge branch 'branch-0.5'
eval-function: Bugfix: 'not' - wrong function name
On startup print current version
Merge branch 'branch-0.5'
Bugfix: list of pseudo elements

- fix commit 3e98451afed98fddb8000e253c3b65b04012936c
Merge branch 'branch-0.5'
pseudo elements: remove debug message
Documentation::eval: fix formatting ( || operator)
Parse Eval: support unary operations + fix operation 'not'
Eval::not: bugfix, use param to check for input not undefined value
pgmapcss v0.5.1 release
Merge branch 'branch-0.5'

Conflicts:
	pgmapcss/version.py