handle empty coverage config option
make tile_lock_dir configurable
write tiles and legends atomical
update documentation for tile_lock_dir
add full example configuration
refactored time functions into util/time
refactored file related functions into util/fs
moved local_base_config() to config package
refactored python related functions to util/py
update module comments in refactored files
add missing __init_.py
update write_atomic tests
fixed formating in wms-capabilities docs
update deployment documentation

- dropped FastCGI docs
- updated titles
- add some clarifications
remove versionadded notes in docs for version <=1.0.0
update install/upgrade documentation

drop old 0.8-0.9 migrate document