clang-analyzer: Fix dead stores in window.c.
clang-analyzer: Reduce scope in spell.c.
clang-analyzer: Reduce scope in screen.c.
clang-analyzer: Reduce scope in search.c.
clang-analyzer: Reduce scope in arabic.c.
clang-analyzer: Reduce scope in syntax.c.
clang-analyzer: Fix dead stores in garray.c.
Travis CI: Refactor travis script

To simplify modification/inclusion of continuous integration targets, this
removes travis.sh which contains a big if statement in favor of multiple scripts
under the new '.ci' directory.
Merge #1046 'Refactor travis script'
Merge pull request #985 from fwalch/clang-analyzer-dead-assignments

Clang analyzer: fix dead stores / reduce scope