Fix image storage enhancement [ER#160: 6bigfire]

Issue littlecodersh#270 (littlecodersh#271)

Make login stoppable in qrCallback [BR#267: githubwing]

Add pushlogin to login without scan qrcode

Fix long contact fetch bug & new protocol of adding friends

Fix contact spelling bug & fix None assignment bug [BR#226: cubesky]

Fix bugs of search_friends and test_connect

Clear useless loggings

Update user warnings

Fix bugs caused by strange contact return values [PR#208: lostdragon]