* SSLConnectionSocketFactory is now SNI-capable, so there's no need
to manage SNI in DAVdroid
* keep secure protocol/cipher suite definitions
* use a patched jar until https://issues.apache.org/jira/browse/HTTPCLIENT-1591 is fixed
* make it work again with non-proxied connections
* add tests for proxied and non-proxied connections
* add tests for SNI, host name and certificate verification
* moved all dependencies to gradle instead of shipping .jar files in the app/lib directory
* switched to official Android port of HttpClient instead of httpclientandroidlib
* new .gitignore and project files