update pymdht pointer to contain some new fixes
Update .gitignore
Merge pull request #813 from whirm/update_gitignore

Update .gitignore
Allow to disable the xlib inithreads() call trough an env variable.
Merge pull request #817 from whirm/optional_initthreads

Allow to disable the xlib inithreads() call trough an env variable.
Merge pull request #812 from LipuFei/update_pymdht

Update pymdht pointer to have some new fixes