Log Message:
Update i3lock to version 2.6.

Changelog:

2014-07-18 i3lock 2.6

 * NEW DEPENDENCY: use libxkbcommon-x11 instead of libX11
   This helps us get rid of all code that directly uses libX11
 * Use cairo_status_to_string for descriptive errors.
 * Add `-e` option to not validate empty password.
 * Bugfix: update the initial keyboard modifier state (Thanks lee, Ran)
 * Re-raise i3lock when obscured in a separate process
 * Turn on the screen on successful authentication
 * Delay to turn off the screen after wrong passwd
 * Discard half-entered passwd after some inactivity
 * Ignore empty passwd after repeated Enter keypress
 * Scale the unlock indicator (for retina displays)

2013-06-09 i3lock 2.5

 * NEW DEPENDENCY: Use libxkbcommon for input handling
   This makes input handling much better for many edge cases.
 * Bugfix: fix argument parsing on ARM (s/char/int/)
 * Bugfix: free(reply) to avoid memory leak
 * Bugfix: Use ev_loop_fork after fork, fixes forking on kqueue based OSes
 * Bugfix: Fix centering the indicator in the no-xinerama case
 * Only use mlock() on Linux, FreeBSD (for example) requires root
 * promote the "could not load image" message from debug to normal
 * s/pam_message/pam_response/ (Thanks Tucos)
 * remove support for NOLIBCAIRO, cairo-xcb is widespread by now
 * Allow XKB_KEY_XF86ScreenSaver as synonym for enter
   This keysym is generated on convertible tablets by pressing a hardware
   lock/unlock button.
 * Allow passwordless PAM conversations (e.g. fingerprint)
 * Add ctrl+u password reset
 * Set window name to i3lock