Linux support

[kkaefer]

• - Get libllmr.a building on Linux - targeting Ubuntu precise with upgraded g++ 4.8 (or 4.7)
• - Add docs to readme for how to get set up on Ubuntu Precise
• - Write a wrapper like we have for osx/ios

[springmeyer]

@kkaefer fyi, linux compile issues with recent commits:

  g++-4.8 '-DNDEBUG' -I../include  -std=c++11 -O3 -I/usr/local/include  -MMD -MF /home/ubuntu/llmr-native/out/Release/.deps//home/ubuntu/llmr-native/out/Release/obj.target/llmr-osx/src/style/sprite.o.d.raw  -c -o /home/ubuntu/llmr-native/out/Release/obj.target/llmr-osx/src/style/sprite.o ../src/style/sprite.cpp
../src/style/sprite.cpp: In member function ‘void llmr::Sprite::loadImage(const string&)’:
../src/style/sprite.cpp:127:46: error: ‘png_const_bytep’ was not declared in this scope
     if (buffer.length < 8 || !png_check_sig((png_const_bytep)buffer.data, 8)) {
                                              ^
../src/style/sprite.cpp:143:88: error: cannot convert ‘uint32_t* {aka unsigned int*}’ to ‘png_uint_32* {aka long unsigned int*}’ for argument ‘3’ to ‘png_uint_32 png_get_IHDR(png_structp, png_infop, png_uint_32*, png_uint_32*, int*, int*, int*, int*, int*)’
         png_get_IHDR(png, info, &width, &height, &depth, &color, &interlace, NULL, NULL);
                                                                                        ^
make[1]: *** [/home/ubuntu/llmr-native/out/Release/obj.target/llmr-osx/src/style/sprite.o] Error 1
make[1]: Leaving directory `/home/ubuntu/llmr-native/out'
make: *** [llmr] Error 2

[incanus]

@ansis @yhahn you guys have any spare cycles for taking a crack at this? We don't have anyone banging on the door for a Linux build, but it would help with testing and it would be good to know how we look here.

[incanus]

this = third checkbox = "Write a wrapper like we have for osx/ios"

[ansis]

I can attempt this next week, probably with plenty of help from @kkaefer

[kkaefer]

👍

[ansis]

A linux wrapper is implemented in linux-wrapper. This should probably be merged with/replace the osx wrapper, but I don't understand gyp well enough to know how to know how to properly merge the gyp files (with the xcode_settings and all that).

[springmeyer]

@ansis - nice work! I'm happy to help with gyp, so I'll take a look at this later today.