0.4.0 Changelist improvements

The latest version of p4ic4idea is now available.

• Major refactoring to the management of changelists.
  • Perforce Changelists are now cached application-wide.
    This allows for code clean-up that should hopefully make
    some of the file migration between changelists
    less common (#22).
• Bug fixes.
  • non-numeric perforce server port (#23)
  • Background threads were causing refresh problems. Turned them
    off to limit the number of issues they caused.
• Add support for IDEA 141.2.2