build: add separate releaselto target for building with lto (and fix it)

This patch contains next hunks:
- leave only used DT_NEEDED tags in output bin in releaselto
    -Wl,--as-needed
- fix releaselto build under clang (input unused for linker options)
    clang accept linker options only for linker without warnings/errors,
    otherwise clang will print an warning/error (IOW during compilation only
    without linking)
- use gold linker for releaselto builds under gcc
    There are some issues with generating NEEDED sections.

And starting from this patch distribution will not use lto.
build: use build dir inside CMAKE_BINARY_DIR by default

This will allow to make less changes for non-release build.
tmuxinator: update hacks for tig v2
tmuxinator: press C-p in vim by default
tmuxinator: more enhanced make window (clang; ninja; mkcd)
tmuxinator: use separate socket to reduce load for default

There are some issues with freeing memory for cells in panes, so it will
be better to use separate socket to allow freeing resources separately.