Avoid using shadow variables. Unfortunately -Wshadow also complains about index variable conflicting with index(), which is used in way too many places to change. --HG-- branch : HEAD

Changed .h ifdef/defines to use <NAME>_H format. --HG-- branch : HEAD

Added "bool" type and changed all ints that were used as booleans to bool. --HG-- branch : HEAD

mail-storage.h interface changes, affects pretty much everything. FETCH, SEARCH, SORT and THREAD handling were pretty much moved from lib-storage/ to imap/ so adding non-index storages would be much easier now. Also POP3 server can now be easily implemented with lib-storage. Not too well tested, and at least one major problem: partial fetching is _slow_. --HG-- branch : HEAD

Naming style changes, finally got tired of most of the typedefs. Also the previous enum -> macro change reverted so that we don't use the highest bit anymore, that's incompatible with old indexes so they will be rebuilt. --HG-- branch : HEAD