fixed muc invite with <body/>.
Fix typos in string resource
Remove full stop in description for consistency
Merge pull request #505 from betheg/fix_invite

fixed muc invite with <body/>.
calculate sample size for thumbnails as well
properly dismiss notifications
show displayed by contact on all devices
avoided unecessary message searchs
mark conversation as read when displayed marker from another client is received
check if display is off for notifications
fixed possible npe
1) Renamed values-zh values-zh_rCN in accordance with #329 and Android conventions
2) Added arrays.xml translations for Simplified Chinese (zh_rCN)
3) Added translations (arrays.xml and strings.xml) for Traditional Chinese (zh_rTW)
Merge pull request #518 from isaackwan/translation_zhrCN-TW2

Chinese Translation fixes
revised tablet ui. fixed #423
bug fixes
fixed chinese translations
let's own otr-fingerprint copy to clipboard.
minor graphic tweaks in copy otr fingerprint to clipboard
implemented ping (xep-0199) fixed #517
minor ui tweak