Since the script storage code is widely engrained in the Pigeonhole sources,
this is a very large commit that cannot be reduced further into smaller
preparatory bits.

It indicates that script execution exceeded a resource limit (currently only CPU
time limit).

The actions contained in the result may keep references to the overriden mail
struct, so these need to be preserved.

This holds a reference to the initial result, causing it to linger after
test_result_reset, thereby also holding a reference to the message context,
preventing it from being cleared. This in turn, can keep references to modified
message versions that cause the main message object to remain referenced. This
causes a panic in specific cases upon test_result_reset:

Panic: Input stream data unexpectedly has references

lib-sieve: Added sieve_script_env_init() to initialize struct sieve_script_env from struct mail_user.

Now using struct smtp_address rather than sieve_address.
In some cases, struct message_address may prove to be more suitable, but this is the best fit for now.
Adjusted to the renamed fields in struct mail_deliver_context.

This adds a new callback to the Sieve script execution environment.

path-util is a merge of realpath from Pigeonhole and abspath from core.

Used the following script:

C_FILES=`git ls-files *.c`
H_FILES=`git ls-files *.h`
for F in "$C_FILES $H_FILES"; do
        echo "$F"
  perl -p -i -e 's/safe_memset\(&\(?([^,]*)\)?,\s*0,\s*sizeof\(\g1\)\)/i_zero_safe(&$1)/g' $F
  perl -p -i -e 's/safe_memset\(([^,]*),\s*0,\s*sizeof\(\*\g1\)\)/i_zero_safe($1)/g' $F
  perl -p -i -e 's/memset\(&\(?([^,]*)\)?,\s*0,\s*sizeof\(\g1\)\)/i_zero(&$1)/g' $F
  perl -p -i -e 's/memset\(([^,]*),\s*0,\s*sizeof\(\*\g1\)\)/i_zero($1)/g' $F
done

lib-sieve: Implemented support for writing runtime trace output to a directory if it exists, much like Dovecot rawlog.

SMTP API now supports adding multiple recipients to a single SMTP transaction. This makes enotify/notify more efficient, since only one message is actually sent.

Patch by Timo Sirainen (modified).

This change is bigger than I would have liked, so this needs to be tested more.

Before, sievec and sieve-dump would switch to mail_uid:mail_gid and then fail to compile/dump a root script.

Added test for interaction between include extension and dict script location support.

Clang static analyzer is happy now.

  - Built generic interface for alternative script sources.
  - Implemented dict script location.
  NOTE: ManageSieve will not work with this yet, nor will sieve_before/sieve_after.

- Added sieve_global_extensions setting.

Configuration is now only read once at extension initialization.