add ramer douglas peucker to the list of simplify converters. also add tests for the simplify converters but so far only testing peucker. also add a method to the wkt factor for converting geometry container to wkt
fix some whitespace issues. somehow tabs were getting in there
standardize commenting convention. i prefer lower case no space (ie laziness) but that doesnt seem to be the norm.
make the simplify test function general purpose so others can add other test cases for other simplification algorithms
tab vs spaces in ide finally fixed. apologies
note to self. read coding convention guidelines before actually writing code.
update variant.hpp (use std::forward<T> for perfect forwarding - via @DennisOSRM)
expression grammar - add boolean_constants and floating_point_constants symbols

```python
>>> import mapnik
>>> f=mapnik.Feature(mapnik.Context(),1)
>>> expr = mapnik.Expression("rad_to_deg * pi")
>>> expr.evaluate(f)
180.0
```
contributing: note that shared/unique_ptr should be used sparingly
C++ test cleanup
upgrade bundled unifont to 7.0.05 and dejavu to 2.34
upgrade scons to 2.3.4
remove unused/supported second arg to parse_expression
adapt to new dejavu version
fix a few -Wunused-parameter warnings
quiet use of mapnik-test-data
c++11 - use c++ style casts + cleanups + use std::fill
use c++ std::fill/copy instead of c-style memset/memcpy
more c++
ImageData -> image_data (remove camel-case)