Doc: Correct and extend infos about LilyDev setup (issue 561360043 by address@hidden)

[michael . kaeppler]

Reviewers: ,

Message:
This patch reflects some changes and small fixed that I contributed to
LilyDev and which are now in the new release v2. 
https://github.com/fedelibre/LilyDev/releases

Description:
Doc: Correct and extend infos about LilyDev setup

* Adjust filenames, setup description etc. to
match LilyDev 2
* Remove information which is no longer valid
* Describe setup procedure more in detail

Please review this at https://codereview.appspot.com/561360043/

Affected files (+114, -62 lines):
  M Documentation/contributor/quick-start.itexi