change default n to 1 to resolve #15
refactor main.py and add null object for code clearance
fix #13 retry in 60s after network error when working in daemon mode
push rev forward to 1.4.3
add collect mode to save accompany pictures with Chinese logo. resolve #14
add help message for collection mode
add warning and help message to clearify path of default config file
add app path retriever
retrieve settings.conf from app path by default to resolve #16
update document ton contain 1.4.3 release notes
add reminding of backup settings.conf before backup
settings.conf can be kept during upgrading or after uninstalling