Clean up DownloadUtils.java

 * Use HEAD request if checking status code
 * Use getResponseCode() instead of parsing TCP stream directly
Merge pull request #723 from jikuja/fixed_downloadutils

Clean up DownloadUtils.java
Clean up DownloadUtils.java

 * Use HEAD request if checking status code
 * Use getResponseCode() instead of parsing TCP stream directly
FIXED: AssetDownloader concurrency

 * Fixed Assetdownloader.doInBackground:
   Moved GUI changing code into EDT
Merge pull request #724 from jikuja/fixed_assetdownloader_concurrency

FIXED: AssetDownloader concurrency
update auth system to be even more secure, ensure that offline mode has UUID's acessible
Merge branch 'master' of github.com:Slowpoke101/FTBLaunch
FIXED: offline mode fixes

 * fixed: Splash screen not closing
 * fixed: AuthlibDLWorker not catching all exceptions caused by network
set UUID for user for offline mode to pick up for use in 1.7.9+
make sure that any json issues don't take down  the auth process,
Merge pull request #725 from jikuja/fix_offline

FIXED: offline mode fixes
FIXED: more offline derps

 * Save userdata after succesfull login
 * Remove unneeded logging
Merge pull request #726 from jikuja/fix_offline_v2

FIXED: more offline derps