ctags.kak: fix support for tags with a tab character in search line
update README
rename BufferManager::complete_buffername to complete_buffer_name
Add ClientManager::complete_client_name
the 'def' commands now supports -(buffer|client)-completion switches
Add g. command to go to the last buffer modification position
Add support for querying client environement variables

At connection, a remote client sends all its environement to the
server, which then provides access to client env through
kak_client_env_VAR_NAME variables in the shell.
client.kak: add a focus command for focusing a certain client.
make,grep: focus jumpclient when jumping to location
update TODO
formatting changes in command_manager.cc
Minor formatting fixes (very long lines)
return a const String& in Option::name()
client.kak: improve termcmd autodetection
Fix select_whole_lines on empty buffer
cpp.kak: tweak comment copy on newline

fixes #92