Removes the version number from the directory name of installed libraries.
Support for installing multiple libraries at once.

ex: use `mkgyp install lib1 lib2` to install both lib1 and lib2 libraries.
Adds .DS_Store to .gitignore.
Prettify the output of installing multiple libraries.
Support for specifying the directory of installed libraries.
Support for installing libraries listed in the "gyp_deps.txt" file at current directory.
Implements the test mechanism and adds test for the lame library.
Makes sure empty lines in `gyp_deps.txt` won't be added as library.
Fixes indentation.
Adds test for faad2.
Updates to test all libraries by not specifying any library name.
Fixes the test mechanism and shows test results.
Adds test for libffi.
Support for detecting failed tests.
Adds test for gtest.
Fixes the mechanism of loading a module dynamically.

The original method may cause error when installing zlib library.
Fixes the issue that testing may fail.
Adds test for zlib.