bumping version numbers and updating changelog for 2.53 (python & java)

updating java changelog, 2.52.0 release

Java changelog and release bump to 2.51.0

bumping to 2.50.1 release, updating changelog

updating java changelog and version number bump for 2.50

py 3.5 on delete doesn't allow new http requests to be made, throws a…

…n exception here

fixes SeleniumHQ#1504

Bump Java to 2.49.0 and update Changelog

updating maven files for httpclient / httpcore update

bumping to 2.48.1

Updating IE driver version for impending 2.48.0 release