Merge pull request #698 from Viper-7/master

FIXED: Not correctly detecting the latest version of 32-bit Java
InstallDirectoryDialog.java: Test installation dir

 * Show error if installing into directory which is write-protected
 * Deny installing into write-protected directory

Signed-off-by: Janne Kujanpää <jikuja@iki.fi>
Merge pull request #699 from jikuja/do_accept_nonwritable_installation_dir

InstallDirectoryDialog.java: Test installation dir
ADDED: Java version detection for OSX