Updated gitignore

Ignore vim comment files, and the build folder (for out of source
builds)
Removed vim swap file

This was an accidental upload.
Fixed gitignore, made makefile cross platform.

Fixed gitignore to actually ignore vim swap files.
Cross platform makefile

The mkdir step, should now work on all platforms.
We want uniform line endings!

The gitattributes file, should ensure that files always have the same
line endings at checkout.
We want crlf endings
Moved clipper to a libraries folder.
Added a DO_NOT_CHANGE_THESE files, nothing developers that the sources in this
folder, is not to be changed directly in this repository, but should rather be
modified in their respective repositories.
Updated the Makefile to build this library.
Updated the Makefile to include the libs folder, as a isystem include
    I.e. do not throw errors, warnings, ect. from these headers.
Updated intpoint, and polygon to include clipper via. compiler lookup.
Merge pull request #76 from Skeen/master

out-of-source building + more
Fix building libclipper.a all the time after #76
Do not force lineends.
Fix c++11 compiling.
Strange shit is happening... how the hell did this happen?.
Add missing util/string.h
Fix MacOS build.
Some cleanup, moved the inside function into the polygon class instead of the comb class. Made all the lineends unix style. Added namespaces.
Merge branch 'master' of github.com:Ultimaker/CuraEngine
Make bridges per fill area instead of per layer.
fix compilation on Linux

src/gcodeExport.cpp:63:23: error: cannot convert ‘fpos_t {aka _G_fpos_t}’ to ‘long int’ for argument ‘2’ to ‘int fseek(FILE*, long int, int)’
     fseek(f, oldPos, SEEK_SET);
Merge pull request #80 from martinxyz/master

fix compilation on Linux
Fix crash bug.