- try to handle even and odd components the same way in the dirichlet group
- switch from phi_q_odd to smaller expo = exponent of the group
all character orders divide this number, and a character of that order exists
- use conrey logarithm to reuse log and to loop efficiently over the group
(see the diff on l.c, only 1 log in computed instead of 2 * q)
- NOT TESTED, for the moment it just compiles, I know some errors
(e.g. the FIXME in group_init.c : the generators have to be lifted mod q)
this commit is just a proof of concept.