Fixed bug in mail_raw implementation: mail_namespaces_deinit() must not be called explicitly for v1.2.

Previously the final value of internal variable was for every store action that didn't
specify a :flags argument explicitly. This results in out-of order assignment/removal
of flags, e.g. also the flags assigned keep actions that were executed before the
addflag/setflag command were modified.

Removed code duplication between testsuite and commandline tools. Also restructured source code of the tools.

Enabled all available mail storage types (those compiled in Dovecot) for the commandline tools and the testsuite.

Merged mail-raw implementations of sieve commandline tools and the testsuite, thus removing duplicate code.

Made lda plugin properly refer to the main script as 'main script' and not the basename of the sieve file (which is of no interest to the user for the main script).