.sh extension for included files

Motivated by Google's shell coding standards. This makes sense for
non-executable files.

src/expect.sh

@@ -22,7 +22,7 @@
 [ -z $__INC_EXPECT_CORE ] || return
 __INC_EXPECT_CORE=1
 
-source expect/output
+source expect/output.sh
 
 
 ##

src/expect/output.sh

@@ -22,7 +22,7 @@
 [ -z $__INC_EXPECT_OUTPUT ] || return
 __INC_EXPECT_OUTPUT=1
 
-source util
+source util.sh
 
 # reserved for our uses
 exec 99<>/dev/null

src/run-spec

@@ -19,7 +19,7 @@
 #  along with this program.  If not, see <http://www.gnu.org/licenses/>.
 ##
 
-source spec
+source spec.sh
 
 declare -r tcase="${1?Missing test case path}"
 

src/spec.sh

@@ -29,8 +29,8 @@
 [ -z $__INC_SPEC ] || return
 __INC_SPEC=1
 
-source specstack
-source expect-core
+source specstack.sh
+source expect.sh
 
 # number of internal arguments before remainder clause
 declare -ir __SHIFTN=3