Revert "IMAP: defer bailout in case of EOF"

This reverts commit afb1d1949e7bb9849e0fe33e4d3ae971711337bd.
Fixed long (>255) utf8 headers + unit-test
Added validation of invalid utf8 sequences (replacing invalid char with "?") + unit-test
Merge branch 'dbmail_3_1_utf8_fix' of https://github.com/alyarskiy/dbmail into dbmail_3_1
fix unit-tests after merge
boundary fix for sha512 passwords #1040
support wrapped boundaries during reconstruction
remove unused file
IMAP: EOF on stdin is not an error
POP3: fix segfault; fixes bug #1043
LMTP/TIMSIEVE: fix possible segfaults
IMAP: fix inverted logic during abort
fix regression in utf7 mailbox matching
Fixed wrong result check in change username function.
IMAP: add loop protection to cleanup callback
version 3.1.11