Add btest for new permission handling

Add a btest for the new permission handling. This is using output of ls
and tar. I'm not positive this will work with variants other than GNU.
If this doesn't work, I'm not sure how to accomplish this portably short
of writing scripts to print out the desired information.

testing/baselines/tests.bundle-permissions/bundle.out

@@ -0,0 +1,38 @@
+### BTest baseline data generated by btest-diff. Do not edit. Use "btest -U/-u" to update. Requires BTest >= 0.63.
+drwxr-xr-x root/root ./
+drwxr-xr-x root/root ./baz/
+-rw-r--r-- root/root ./baz/__load__.zeek
+-rw-r--r-- root/root ./baz/zkg.meta
+-rw-r--r-- root/root ./manifest.txt
+drwxr-xr-x root/root ./rot13/
+-rw-r--r-- root/root ./rot13/CHANGES
+-rw-r--r-- root/root ./rot13/CMakeLists.txt
+-rw-r--r-- root/root ./rot13/COPYING.edit-me
+-rw-r--r-- root/root ./rot13/Makefile
+-rw-r--r-- root/root ./rot13/README
+-rw-r--r-- root/root ./rot13/VERSION
+-rwxr-xr-x root/root ./rot13/configure
+-rw-r--r-- root/root ./rot13/configure.plugin
+drwxr-xr-x root/root ./rot13/scripts/
+drwxr-xr-x root/root ./rot13/scripts/Demo/
+drwxr-xr-x root/root ./rot13/scripts/Demo/Rot13/
+-rw-r--r-- root/root ./rot13/scripts/Demo/Rot13/__load__.zeek
+-rw-r--r-- root/root ./rot13/scripts/__load__.zeek
+-rw-r--r-- root/root ./rot13/scripts/__preload__.zeek
+-rw-r--r-- root/root ./rot13/scripts/init.zeek
+-rw-r--r-- root/root ./rot13/scripts/types.zeek
+drwxr-xr-x root/root ./rot13/src/
+-rw-r--r-- root/root ./rot13/src/Plugin.cc
+-rw-r--r-- root/root ./rot13/src/Plugin.h
+-rw-r--r-- root/root ./rot13/src/rot13.bif
+drwxr-xr-x root/root ./rot13/testing/
+drwxr-xr-x root/root ./rot13/testing/Baseline/
+drwxr-xr-x root/root ./rot13/testing/Baseline/tests.main/
+-rw-r--r-- root/root ./rot13/testing/Baseline/tests.main/output
+drwxr-xr-x root/root ./rot13/testing/Baseline/tests.rot13/
+-rw-r--r-- root/root ./rot13/testing/Baseline/tests.rot13/output
+-rw-r--r-- root/root ./rot13/testing/btest.cfg
+drwxr-xr-x root/root ./rot13/testing/tests/
+-rw-r--r-- root/root ./rot13/testing/tests/main
+-rw-r--r-- root/root ./rot13/testing/tests/rot13
+-rw-r--r-- root/root ./rot13/zkg.meta

testing/baselines/tests.bundle-permissions/unbundle.out

@@ -0,0 +1,20 @@
+### BTest baseline data generated by btest-diff. Do not edit. Use "btest -U/-u" to update. Requires BTest >= 0.63.
+state/clones/package/rot13:
+total 52
+drwxr-x--- 5 esk esk 4096 omitted build
+-rw-r--r-- 1 esk esk    0 omitted CHANGES
+-rw-r--r-- 1 esk esk  241 omitted CMakeLists.txt
+-rwxr-xr-x 1 esk esk 5329 omitted configure
+-rw-r--r-- 1 esk esk  380 omitted configure.plugin
+-rw-r--r-- 1 esk esk 1707 omitted COPYING.edit-me
+-rw-r--r-- 1 esk esk  704 omitted Makefile
+-rw-r--r-- 1 esk esk   84 omitted README
+drwxr-xr-x 3 esk esk 4096 omitted scripts
+drwxr-xr-x 2 esk esk 4096 omitted src
+drwxr-xr-x 4 esk esk 4096 omitted testing
+-rw-r--r-- 1 esk esk    4 omitted VERSION
+-rw-r--r-- 1 esk esk  122 omitted zkg.meta
+
+state/script_dir/packages/rot13:
+total 4
+-rw-r--r-- 1 esk esk 186 omitted __load__.zeek

testing/tests/bundle-permissions

@@ -0,0 +1,33 @@
+# @TEST-EXEC: bash %INPUT
+
+# @TEST-EXEC: zkg purge
+# @TEST-EXEC: umask 0027 && zkg bundle test.bundle --manifest manifest.txt
+
+# FIXME: this may be specific to gnu tar output format
+# @TEST-EXEC: tar tvf test.bundle | grep -v git | tr -s ' ' | cut -f 1,2,6 -d ' ' > bundle.out
+# @TEST-EXEC: btest-diff bundle.out
+# @TEST-EXEC: umask 0027 && zkg --config=my_zkg.config unbundle --force --replace test.bundle
+
+# FIXME: this may be a gnu-specific option, and output may differ based on ls implementation
+# @TEST-EXEC: ls -l --time-style=+omitted state/script_dir/packages/rot13 state/clones/package/rot13 | grep -v 'git\|dist' > unbundle.out
+# @TEST-EXEC: btest-diff unbundle.out
+
+# make sure the on-disk permissions will differ
+chmod -R g-w,o-rwx packages/rot13
+
+echo "$(pwd)/packages/rot13" >> sources/one/bob/zkg.index
+cd sources/one
+git commit -am 'add rot13 package'
+cd ../..
+
+echo "[bundle]" > manifest.txt
+default_branch_name=$( cd packages/baz && git rev-parse --abbrev-ref HEAD )
+echo "baz = ${default_branch_name}" >> manifest.txt
+default_branch_name=$( cd packages/rot13 && git rev-parse --abbrev-ref HEAD )
+echo "rot13 = ${default_branch_name}" >> manifest.txt
+
+cat << EOF > my_zkg.config
+[paths]
+state_dir = $(pwd)/state
+
+EOF