configure: Add spaces after <<EOF heredoc markers for clarity

I mean, they confuse the vim bash syntax highlighter
configure: Let the user enable both built-in protocols and purple

There's no real risk in enabling these, since protocols/purple/purple.c
already avoids adding duplicate protocols in purple_initmodule():

    /* If we already have this one (as a native module), don't
       add a libpurple duplicate. */
    if( find_protocol( prot->info->id ) )
        continue;
doc/bitlbee.xinetd: Move -I to server_args
Fix version in pkg-config file, also change bzr version format slightly

Old bzr version format: bzr-1234
New bzr version format: 3.2.1-bzr-1234

Version spoofing with the BITLBEE_VERSION also changed slightly - it
does not need quotes around the version number anymore for it to compile
correctly.
Fix double slashes in systemd unit templates
Two small fixes to make Debian builds work again.
Nope, do not install systemd stuff by default. Remove it from the install:
dependencies and tell the user to run "make install-systemd" in cases where
this seems useful.
3.2.2. Last revisions pretty much all done and/or merged by dx!
Remove libotr2-dev Debian dependency which couldn't possibly work at all.
Add limit param to split_command_parts(), fix twitter quotes bug

Only took me a few months to write. I even added a test case.