start Hecke characters class using pari
Hecke characters class
use Sage ideals
add Hecke characters in WebCharacter
change template: restrict computation to Dirichlet chars (+ fix bug on sign)
add Hecke chars

- add route to website.py
- new Characters.py file (mimics DirichletCharacter.py, should be more general)
add values on generators for Hecke characters
add Galois orbit, improve labels

+ add functions to find previous and next character
Add minimal page for Hecke character group
documenting keys exported for different chars
update doc for characters
Rewrite characters, should be more readable and faster

not finished, not tested
confirm knowl titles for characters
use classes for all web chars objects
fix property calls
fix typo
fix typo
fix order() and print debug info
fix template routes
fix template routes