Configurable icon position

[Azuritul]

Bumped the version to 1.0.0!!

Feature

• [x] Added config option: itemImagePosition. Default is .Prefix

  Fix

• [x] Fix build warning in xcode

  Enhancements

• [x] The structure of sample program is updated.
• [x] Icons used in the sample program are moved to xcassets.
• [x] Names used in code's license block are made consistent( use my full name instead of nickname).

  Others

• [x] Updated screenshot.
• [x] Added CHANGELOG.md
• [x] Replaced icon set with a new one. Previous Glyphicons are removed.

[Azuritul]

Travis check passed accordingly. Odd results happened after I mistakenly added too many ci service and did not take care of their configuration. Now I already disabled the hook to those services and they shouldn't be triggered next time.