add tset in Gis
add invfreqz
erge branch 'master' of https://github.com/pylayers/pylayers

Conflicts:
	pylayers/antprop/channel.py
improvement in polar function for polar diagram in D2.4
Merge branch 'master' of https://github.com/pylayers/pylayers

Conflicts:
	pylayers/antprop/channel.py
Merge branch 'master' of github.com:pylayers/pylayers
- Modify ntheta/nphi to Nt/Np (from Fpatt)
- bug fix default Gauss pattern
- bug fix in polar
- bug fix in locbas (self.tang => self.tangl)
- improvement in plotd
- add plotad to vizualize Phi vs delays
- eval now pass a tangl and rangl to ctilde
- add a backtrace argument to run4 to allow visiting nodes already
  visited(experimental)
minor bug fix