preprocess: replace recursively to allow nested for-loops
Documentation Default Base-Style: add z-index
Implement *-major-z-index
Example 'Roads Parks': no need to use different pseudo element for labels
Compile: sort all-major-z-index ascending
Default Base-Style: add casing-*
MapCSS: support rgb() syntax
MapCSS: support url() syntax
pgmapcss_parse_properties(): save type of value
Compiling properties: Do not cast to text
Define type of properties as @type
MapCSS: If type of a property != text, use pgmapcss_type_* function instead
MapCSS: rewrote last commit, compile type 'tag_value' in pgmapcss_compile_statement()
MapCSS: Disable rules with pseudo classes
Eval: implement missing eval functions

- rename number() to metric()
- MapCSS 0.2 functions: int, num, metric, zmetric (not done, just a template),
  str
- further functions: round
Eval: some functions only accept int as parameter (get, set, round)
Eval:: +, -, *, /, sqrt: convert none to 0
Eval::div: bugfix
MapCSS: @default_other -> default values of other properties
Default Base-Style: @default_other properties