Introduce auto resolution support for current feature/release/hotfix

[bhagyas]

Suggestion to introduce dynamic current branch detection.

Instead of using git flow feature finish my-feature-1 when you are already in feature/my-feature-1 I suggest introducing a new keyword to automatically detect and publish/finish it. An example syntax would be to use git flow current feature finish.

current would be an alias for the current working feature/release/hotfix as detected through parsing the branch name.

Examples:

• git flow current feature publish
• git flow current feature finish
• git flow current hotfix publish
• git flow current hotfix finish