Make running the tests a little easier on Windows

1.  Set the igncr option a little differently, this is the preferred
    way according to the latest Cygwin bash update announcement
    (See https://sourceware.org/ml/cygwin-announce/2014-10/msg00015.html, Sect 4a)
    The previous way didn't work for me.
2.  Ensure /usr/bin is on the path if running under Cygwin.
    I really don't want Cygwin on my normal paths, the build process
    adds if required, so this change makes the test scripts do the same.

Change-Id: I0f4da1fa87802bf0a4039bb5a91e577fae506d79
Reviewed-on: https://code.wireshark.org/review/6243
Tested-by: Graham Bloice <graham.bloice@trihedral.com>
Reviewed-by: Gerald Combs <gerald@wireshark.org>
Petri-Dish: Graham Bloice <graham.bloice@trihedral.com>
Tested-by: Petri Dish Buildbot <buildbot-no-reply@wireshark.org>
Reviewed-by: Graham Bloice <graham.bloice@trihedral.com>

test/test.sh

@@ -1,7 +1,7 @@
 #!/bin/bash
-(shopt -s igncr) 2>/dev/null && shopt -s igncr; # comment is needed
-#                                               # hack for cygwin bash
-#                                               #  no-op for other
+(set -o igncr) 2>/dev/null && set -o igncr; # comment is needed
+#                                           # hack for cygwin bash
+#                                           #  no-op for other
 #
 # Test various command line testable aspects of the Wireshark tools
 #
@@ -29,6 +29,11 @@ USE_COLOR=1
 RUN_SUITE=""
 PRINT_USAGE=0
 
+# Ensure cygwin bin dir is on the path if running under it
+if [[ $OSTYPE == "cygwin" ]]; then
+	PATH="/usr/bin:$PATH"
+fi
+
 while getopts "chs:" OPTION ; do
 	case $OPTION in
 		c) USE_COLOR=0 ;;