distinguish icon for HTML mail and other mail with attachments on summaryview (#84).
libsylph/procmime.[ch]: added procmime_get_part_fp_fp().
implemented concatenation of partial messages (RFC 2046).
use quoted-printable or base64 to protect trailing spaces on PGP/MIME signing except for ISO-2022-JP.
merged from libsylph branch.
added signature information to MsgInfo.
removed metamail support and replaced it with the alternative implementation.
force attaching of specific types on forwarding even if filename is unspecified.
implemented 'Save all'.
changed the license of LibSylph from GPL to LGPL.
moved more modules to libsylph.
made the file size of attachments more accurate, and human-readable.
implemented 'Save this image as...' in the context menu of inline images.
use Content-Type's charset as a fallback encoding of broken header strings.
output printing text with locale encoding, and removed broken locale specific HTML entity reference conversion.
implemented inline image display.
Initial import of Sylpheed (GTK2 version).