Log Message:
Update "xchat" package to version 1.8.11. Changes since version 1.8.10:
- Updated Turkish translation (Fatih Demir).
- Updated Swedish translation (Christian Rose).
- Updated Spanish translation (Julio Merino).
- Fixed /ME in dialog windows.
- Support up to 4GB files in DCC (previously 2GB).
- Fixed random /part reasons not working.
- Fixed possible crash when receiving a message from a channel that
  was already parted.
- Updated included intl/ to 0.10.38.
- Updated build environment to autoconf 2.53.
- Fixed tabcompletion crash on very large channels.
- Fixed glibc 2.3.x regexp channel-list window crash.
- Don't leak memory on /unloadall.
- win32: convert \ and | to _ when receiving filenames with nick.
- win32: don't use TerminateThread(), which leaks the stack.