update changelog
scons: only link in libraries that are required by the build
only build tiff/png readers if support is requested
scons: enable control of shpindex and svg2png tools
formatting as per c++ style
Use path.join instead of string concatenation.
support boost::hash() for mapnik::value
use multiple processors by default
fix _MSC_VER typo.
Merge pull request #1731 from avlee/pythontests

python tests
Merge pull request #1729 from kkaefer/value_hash

Support boost::hash() for mapnik::value
Merge pull request #1730 from kkaefer/multicore-build

Use multiple processors by default
fix mapnik::value for boost 1.49 and other icu versions
Merge pull request #1733 from kkaefer/value_hash

Fix mapnik::value for boost 1.49 and other icu versions
- improved oracle sub-select handling
- fixed a logic problem of the rowlimit clause (when using seb-selects)
- applied tokens to the query (much like the postgis datasource)
- leave oracle to convert most datatypes (should fix occi part of ref #1672)
Merge branch 'master' of github.com:mapnik/mapnik into map-request
further refine the mapnik::request object which can be passed to custom agg_renderer