sql: Add dependency on TCL shell for linux in Travis

SQLite uses TCL shell to generate common headers.
Add dependency in Travis to TCL shell for linux targets.
OSX comes with TCL pre-installed - no need to add dependency.

	* .travis.mk (deps_linux): Add tcl.

sql: Add dependency to TCL in packages.

As far as SQLite sources depend on TCLsh we need to
add dependency to TCL in package info.

	* debian/control: Add dependency on TCL.
	* rpm/tarantool.spec: Ditto.
	* snapcraft.yaml: Ditto.

sql: Avoid multiline string to satisfy older cmake

RHEL uses some old cmake which doesn't work with long string
which span over few lines w/ '\' terminator. Make it single line.

	* src/box/CMakeLists.txt (set_source_files_properties): Use
	single line instead of vreaks w/ '\'.