Changes from Ant 1.9.0 TO Ant 1.9.1

Changes that could break older environments:

 * Users who have their own ProjectHelper implementation will need to change it because the import and include tasks
   will now default the targetPrefix to ProjectHelper.USE_PROJECT_NAME_AS_TARGET_PREFIX.
   Users using the default ProjectHelper2 with ant need not worry about this change done to fix Bugzilla Report 54940.

Fixed bugs:

 * Corrected XSLTC error in <junitreport>.
   Bugzilla Report 54641.

 * Provide more control over Zip64 extensions created by <zip> and
   related tasks.  In particular no Zip64 extensions will be used at
   all by the <jar> task family by default - this is required for jars
   to be readably by Java5.
   Bugzilla Report 54762.

 * Fixed loading of external dependencies in JUnit task.
   Bugzilla Report 54835.

 * Target rewriting for nested "include" only works when "as" is specified.
   See also "Changes that could break older environments"
   Bugzilla Report 54940.

Other changes:

 * strict attribute added to <signjar>.
   Bugzilla Report 54889.

 * simplifying Execute.getEnvironmentVariables since we are only running on Java 1.5 or higher now

 * Add conditional attributes
   Bugzilla report 43362

 * Recommending to upgrade jsch to 0.1.50, particularly if you are using Java 1.7.
   jsch is the library behind the sshexec and scp Ant tasks.
   Versions of jsch older than 0.1.50 fail randomly under Java 1.7 with an error message "verify: false"