Adds download-deps.py
Removed download-deps.sh
Updates download-deps.py
Updates download-deps.py
Updates download-deps.py
Updates before-install.sh
Merge pull request #6561 from dumganhar/v3

Uses 'download-deps.py' to download Cocos2D-X dependence files
Updates download-deps.py, write file with permission information while unziping.
Merge pull request #6563 from dumganhar/v3

Updates download-deps.py, write file with permission information while unziping.
Update download-deps.py
Updates download-dep.py, linux and mac works ok
Removed pkg_resources dependence
Uncomment a line in download-deps.py
Merge pull request #6564 from dumganhar/v3

Updates download-dep.py, linux, mac  and windows work ok
Small bug fix in download-deps.py
Don't remove .zip file, if it exists, don't download it.
Updates .gitignore
Merge pull request #6565 from dumganhar/v3

Small bug fix in download-deps.py
Adds download progress for download-deps.py
Re-adds missing luajit sources.