lib-imap: Make imap_bodystructure_parse_args() public

lib-imap: imap-bodystructure: Added support for making imap_bodystructure_parse() work without a pre-existing message_part tree. It can now create the tree from the BODYSTRUCTURE string itself.

lib-imap: imap-bodystructure: Moved message_part_data header parsing and query functions to their own module in lib-mail. Moved code from imap-bodystructure and imap-envelope.

lib-imap: imap-bodystructure: Renamed imap_bodystructure_is_plain_7bit() to message_part_data_is_plain_7bit().

lib-imap: imap-bodystructure: Renamed imap_bodystructure_parse_header() to message_part_data_parse_from_header().

lib-imap: imap-bodystructure: Changed struct message_part_body to contain fully decoded data. Contained unparsed IMAP string data before.

lib-imap: imap-bodystructure: Removed useless pool field from struct message_part_data.

lib-mail: Gave message_part_data its own field in struct message_part.

lib-imap: imap-bodystructure: Renamed struct message_part_body_data to message_part_data.

imap-bodystructure.h comment fix

imap-bodystructure.h comment update

lib-imap: Added support for parsing IMAP BODYSTRUCTURE and writing out a modified version.

imap_body_parse_from_bodystructure() now returns the error instead of logging it.

Added more consts, ATTR_CONSTs and ATTR_PUREs. --HG-- branch : HEAD

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

Make imap_bodystructure_write() parameter constant. Patch by Max Kellermann --HG-- branch : HEAD

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

Added imap_bodystructure_is_plain_7bit() --HG-- branch : HEAD

Cache file fixes, API changes, etc. It's still in somewhat ugly state, but getting better.. --HG-- branch : HEAD

Removed unneeded code --HG-- branch : HEAD

If BODY/BODYSTRUCTURE is requested with some other headers, parse the headers only once. If body contains multiple MIME parts, cache the internal MIME structure so BODY[part] fetching doesn't need to parse it again. --HG-- branch : HEAD

comment update --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

Renamed IBuffer and OBuffer to IStream and OStream which describes their functionality better. I tried to keep the variable names and comments also sensible. --HG-- branch : HEAD

If BODYSTRUCTURE is cached, we can use it to generate BODY reply. It takes some CPU, but probably still faster than needing to open the file. Also removed requirement of FIELD_TYPE_LOCATION to exist in .data file. This will be useful when we don't need the location (eg. filename == uid). --HG-- branch : HEAD

Split IOBuffer into mmaped IBuffer, file IBuffer, memory data IBuffer and file OBuffer. --HG-- branch : HEAD

Message data is parsed in blocks (no longer entirely mmap()ed). Several IOBuffer changes. All mixed signed/unsigned comparisions were fixed so code can now be compiled with gcc's -W flag. mbox support is broken currently, and there's most likely several other problems too. --HG-- branch : HEAD

Initial revision --HG-- branch : HEAD