Add Skill Plan management into evething

Add models, views, static files (js/css). (I think I did not rebuild static data with the makefile yet)
Add skillplan (works like before) in a specific page (not anymore in "account settings") and you can
- import from .emp (already existing) from evemon
- export to .emp to evemon
- add skills / remap points (and optimize them)
- add skills from an eft fit (clipboard)

You still view it like before, from a character sheet, the "view" (from editing page).

Some other changes:
- Changed some icons to show already trained skills, currently training, partially trained, 
- add a column with time left on skillplan (not shown by default)
- show total time you will be using a remap point
- show total time with / without already trained skills (only when you shows "already trained skills" to see how much time left / total)

Added skillplan into the readme with some screens (better than none)

Changed import (and models) to import skill prerequisites for every items (required for skills and EFT fits import)

Just to say this pull request includes already both pull-request https://github.com/madcowfred/evething/pull/36 and https://github.com/madcowfred/evething/pull/35

Hope it helps and that you'll find it useful