Update drush formula to 5.5

http://drupal.org/node/1719512

Release notes

Changes since 7.x-5.4:

Removing reference to defunct http://drupal.org/project/make in generated PATCHES.txt files.
#832472: Give advice on the "can't connect to local MySQL server through socket" error
Clarify sql-sync policy.
Change reset() with current() to avoid 'pass by reference' warnings
Fix problem in _drush_shell_exec when pre-escaped command may contain args with % characters, which breaks sprintf
better help text on make option.
#1710102: array_key_exists() expects parameter 2 to be array, boolean given sql.drush.inc:855
#1706738: Clean up mime type detection and tarball management
#1706666: drush_download_file() doesn't generate $destination
Follow-up to issue #1343058: remove querystring from filename to allow detection of file type by extension
Follow-up to issue #1343058: Fix finfo_file output parsing
#1343058: Add support for extracting .tar.bz2 files
#1595050: Add backward compatibility for 'Install profiles'.
#1704678: Cache clear of theme registry should use drupal_theme_rebuild()
#1673006 by damiankloip: Add --exect option for vget and vset
#1623328 by greg.1.anderson: In core-config command, run in foreground by default, unless --bg flag is specified.
#1673814 by greg.1.anderson: Set 'interactive' in backend options if --interactive command specified from command line.
#1679418 by msonnabaum: Don't add extra newline on --pipe
#1430482 by janusman, greg.1.anderson, jamesharv: Drush archive-dump tar options
#1679324 by ao2: Fixed Typo in drush_sql_build_createdb_sql() doc.
#1678294: add missing quotes in example.aliases.drushrc.php
#1649368: Enabling/Disabling modules does not clear cache (menu)
#1677708: Allow --db-su without --db-su-pw
Fix #987968 by moshe weitzman. Document hook_drush_command in api file.
#1672200: Typo in drush_get_option example
#1671870: Make clear that --database option requires a value
#1674796: Have mercy on Drush 5.x users with Drupal 5 sites
#1677536: Update cdd bash alias to use new way of calling remote site commands
#1403076 by greg.1.anderson: remove unnecessary notice in drush_escapeshellarg
Fixing bug in issue #1633050 where unexpanded project arrays failed to build with defaults.
#1650426 by juampy: Test archive-restore.
#1642532 by Damien Tournoud: Fixed Race condition in drush_mkdir().
#1647620 by juampy: Tests do not use sites/default.
#1659668 by duellj: Fixed variable-get outputs in single line when using --pipe.
#1633050 by jhedstrom: Added Create defaults array in .make files for specifying attributes common to all projects.
#1543774 by helmo | sylus: Fixed Drush Make + Undefined Translations.
#1649600 by greg.1.anderson: Alter permissions after sql-sync in examples/sync_enable.drush.inc
#1509936 by juampy | filler: Fixed archive dump ard puts default.settings.php into the archive twice which errors on archive restore arr.
#1645788 by greggles: Fixed if user is blocked throw a warning instead of returning a login link.
Try to get list to show up nicely at http://api.drush.org/api/drush/includes%21sitealias.inc/function/drush_s.... Using some code conventions from http://drupal.org/node/1354#lists.
#1627874 by koglinjg: Fixed typo in documentation.
#1604648 by dmitry_bezer: Fixed Make tests fail on windows.
#1630220 by Damien Tournoud, Moshe Weitzman: Fixed Cache inconsistency lead to 'wrong md5 checksum' on dev releases.
Follow-up to #1528422: fix undefined variable breaking .info file rewriting for dev versions.
#1624904: Missing a word in DRUSH_COMMAND_INSUFFICIENT_BOOTSTRAP
Remove a stray --self-update in upc test.
#1616416 by helmo: Better use of phpnunit assertFileExists method.
#1619042 by moshe weitzman and JulienD. Don't do self-update check during updatecode. Remove docs from example.drushrc.php
#1616416 by helmo: Added Cleanup patch.
#1550574 by Steven Jones: Pass through alias in drush_invoke_process when dispatch-using-alias is set.
#1528422 by fabsor | Steven Jones: Patches no longer apply because of info file re-writing.