source codes moved to git.txt

The SoundTouch source codes have been migrated to git. The new git repository is:
https://gitlab.com/soundtouch/soundtouch

The new git repository also contains tags for the earlier soundtouch releases, for example release v2.0.0 is available at:
https://gitlab.com/soundtouch/soundtouch/tree/soundtouch-2.0.0

This subversion repository still contains the earlier tagged soundtouch releases. The last SoundTouch version available in subversion repo is v2.0.0 at:
https://svn.code.sf.net/p/soundtouch/code/tags/soundtouch-2.0.0