Partially fix issue #66.

Report: javascript filters do not display all offers when asked to do
so. Part of the issue was from the COntractFilter which looked for
exact contract description (either "CDD" or "CDI" ...) instead of a
likeness between the selected contract type names and the contract
description. This, is fixed.
Partially fix #66.

Contracts which do not fit in the predefined contract types (CDI, CDD,
Internship, Alternance?) are considered gibberish and displayed. This
fixes almost completely #66. THere is still a f***ing job offer whom
the js filters hide.
fixup! Report: change default text on dropdown menus.
Report: remove debug messages.
Report: remove code of TypeFilter construction.
Report: salary filter, handle coma as digit separator.

May fix #66.
Report: fix issue #66 :)