readme: added information on how to generate the escape character

Make sure that users understand that on  different kayboard layouts you will have different ways of generating the escape character
readme: small changes to make the escape character generation look better

Changed it to proper code spans
Merge pull request #192 from virtualswede/master

readme: added information on how to generate the escape character
appc: remove remaining smartquotes in spec
cas: use tmpdir for tests
Merge pull request #207 from jonboulle/cas_test_tmp

cas: use tmpdir for tests
Merge pull request #211 from jonboulle/fix_quotes

appc: remove remaining smartquotes in spec
appc/spec: minor tweak to mountpoints
Merge pull request #205 from jonboulle/spec_mounts

appc/spec: minor tweak to mountpoints
appc/actool: remove unnecessary execute bits actool build output

Group and other execute bits are inappropriate for the produced .aci and
embedded app manifest files
Merge pull request #213 from vcaputo/urwgor

appc/actool: remove execute bits from build-created aci file mode