fish: don't override title when using dtach+dvtm

Signed-off-by: Christopher Larson <kergoth@gmail.com>
fish: move context config load farther down

Needed to ensure context files can override everything.

Signed-off-by: Christopher Larson <kergoth@gmail.com>
fish: set NCURSES_NO_UTF8_ACS=1

Works around issues with mosh and line drawing characters with dvtm.

Signed-off-by: Christopher Larson <kergoth@gmail.com>