remove calls to Sage dirichlet characters

these were very slow

+ add jinja loopcontrol to allow easy truncation of large data from template
Merge branch 'master' into remove-sage-character-calls
Merge pull request #154 from pascalmolin/remove-sage-character-calls

Remove sage character calls and enable jinja2/loopcontrol
fix lmfdb base, but should remove this file
fix dbport import everywhere
move stupid file from main level

(by the way, why is it on master ?)
IMPORTANT: remove the doctest flag

with the flag, all .py files are run when a test is run, in particular
the database scripts, which is very bad.
Merge branch 'master' into fix-tests
change Lfunction to use Jonathan's character code

still the lcalc is called from sage, hence uses the sage character in the end
should also be changed if one wants to be able to display larger character L functions
disable HGM test since the HGM are not available