Adds support for the library_dirs key, which appears in the documentation but was never actually im…

pylib/gyp/generator/scons.py

Index: pylib/gyp/generator/scons.py
===================================================================
--- pylib/gyp/generator/scons.py	(revision 1429)
+++ pylib/gyp/generator/scons.py	(working copy)
@@ -214,6 +214,7 @@
       'CXXFLAGS' : 'cflags_cc',
       'CPPDEFINES' : 'defines',
       'CPPPATH' : 'include_dirs',
+      'LIBPATH' : 'library_dirs',
       # Add the ldflags value to $LINKFLAGS, but not $SHLINKFLAGS.
       # SCons defines $SHLINKFLAGS to incorporate $LINKFLAGS, so
       # listing both here would case 'ldflags' to get appended to
@@ -227,7 +228,7 @@
       if value:
         if gyp_var in ('defines',):
           value = [EscapeCppDefine(v) for v in value]
-        if gyp_var in ('include_dirs',):
+        if gyp_var in ('library_dirs', 'include_dirs',):
           if src_dir and not src_dir.endswith('/'):
             src_dir += '/'
           result = []