Add option to use a diff to update pbf file if specified in country configuration
Get correct state.txt file when not using minute diffs
Set diff_path in config
Set JAVACMD_OPTIONS at the beginning, and add support for http_proxy
Add min_file_size to module download.py
File state.txt is quite small, so lower min_file_size
Check if pbf file exists when applying diffs
Set diff path for all countries downloaded from geofabrik
Merge branch 'osmosis_replication'

This should reduce bandwidth used by downloading diff instead of whole .pbf
file from Geofabrik, at the cost of a little local disk space.
Print sql request in case of exception when executing it