redirect trailing slash urls
get rid of rack security warning in dev mode
add fetamont font
allow rational numbers in metafont files

e.g. a number 20/30 is valid when defined in font.mf
don't write hidden parameters to mf file
use key for font params

this is actually a bug, as we haven't used the key for mapping the
params from the ui to the db. also, the params were saved with the wrong
name in the db.

we haven't detected this as per coincidence the dasherized names were
equal to the key.
remove special handling for storing yaml

as it seems this is not necessary. maybe with the update of datamapper this
became obsolete. maybe this hasn't worked properly at all.
re-arrange app into new directories

* new config directory for all configs
* everything app related goes into app/ (views, lib, ...)