https://github.com/prusa3d/Slic3r/issues/443
Change of the PlaceholderParser:
All vector configuration values stored into the PlaceholderParser
are expected to be addressed by the extruder ID, therefore
if a vector configuration value is addressed without an index,
a current extruder ID is used.
Also a small fix of fan handling: The fan speed is set to zero
at the start of the G-code if the cooling for the initial extruder
is disabled.
Removed GCode.pm
Removed the Perl bindigns for AvoidCrossingPerimeters, OozePrevention, SpiralVase, Wipe
Changed the std::set of extruder IDs to vector of IDs.
Removed some MSVC compiler warnings, removed obnoxious compiler warnings when compiling the Perl bindings.
Updated xs/Build.PL to understand BOOST_LIBRARY_PATH and
BOOST_INCLUDE_PATH environment variables. This way one may easily
switch between various boost builds.
Some minor tweeks were done to make Slic3r compile with
Visual Studio 2013.
