Fixed compile errors cased by recent git4idea changes in IDEA14 EAP

- GitHttpAuthDataProvider getAuthData interface changed to require ModalityState
 - See: https://github.com/JetBrains/intellij-community/commit/13963225d1a04265c48c73b31ab22e05f5e3c9a8
- GitLineHandlerPasswordRequestAware removed as obsolete
  - See: https://github.com/JetBrains/intellij-community/commit/f3eb2b26b6d434fad428f447758dae1dbf4876bf