Adding gk's key for verifying tags, too.
Bump versions for nightlies.
Bump lang pack version, too.
Peparing 4.5-alpha-2.

Bump Torbutton, NoScript and HTTPS Everywhere version. Update
config.yml and ChangeLog.
Correct NoScript hash.
Updated Changelog for 4.5-alpha-2.
Bug #13776: Incremental MAR files not reproducible

Set the locale and umask to avoid differences across systems and users when
generating incremental MAR files.
Bug 13379: Sign our MAR files.

In the Linux mar-tools package, include certutil, signmar, and the required
  NSS and NSPR libraries.
Change update_responses to select the action to be done based on the
  program name, thereby separating the incremental MAR file generation (done
  via a new 'gen_incrementals' symlink) from the htdocs generation.  Also added
  an 'update_responses' make target.  Thanks to boklm for help with this.
Add a series of 'signmar' make targets which run a new signmars.sh script,
which does the following:
  1. Prompts for an NSS password (the script assumes that an nssdb directory
     exists that contains the signing key/cert).
  2. Moves original (unsigned) MAR files to a TORBROWSER_VERSION-unsigned/
     directory.
  3. Signs each of the MAR files, placing the signed files in the
     TORBROWSER_VERSION/ directory.
  You may set NSS_DB_DIR and/or NSS_CERTNAME before running signmars.sh; the
  defaults are ./nssdb and marsigner
Updating the README.build.

This update takes account of the changes landed in #13379 and earlier
updater related bugs. It removes the section with spurious hangs during
builds as the underlying libfaketime problems should be fixed with the
switch to a newer libfaketime providing a more fine-grained control via
FAKETIME_SKIP_CMDS and friends.