Valhalla fix

[farfromrefug]

So as i mentionned here #2
with sub osm extract the valhalla build scripts seems to be looking for the wrong tiles.
I fixed in the way :

• store the bbox of the poly for each package
• compute vtiles using this

It is also much faster as building tiles list from tilemask seems pretty slow.
In this case it means the tilemask is actually not needed anymore.

There is also code cleanup of consequently unecessary code and a VACUUM cleanup

[mtehver]

The original issue is now fixed. I am not sure we need any of the other changes, as bounding box itself can be calculated from tile mask and is thus redundant. Also, the original script is quite fast when used with pypy, which is the recommended Python implementation when processing offline packages.

[farfromrefug]

@mtehver i ll test your new implementation and report