Remove unused variable
Remove mentions of register

C++ 11 Standard (Annex D.2):

The use of the register keyword as a storage-class-specifier (7.1.1) is
deprecated.
Remove unused or undefined functions
Add required virtual destructors.
Return proper NULL delimiter

NULL will get cast to (char)0 properly, but casting ‘\0’ (technically
an int) better expresses the intent that we mean to return the
terminating char.
Fix PR comments
Build fixes for Linux
Merge pull request #535 from CodaFi/W-Pedantic-Warnings

Cleans up warnings
Improved charset conversion. Added TODOs.
Fixed #531, #530, #529, #528, #527: fixed thread safety in case callback is dispatched in a thread different than main thread.
Added comment
Fixed charset detection, improved collection of valid charset (fixed #532)
Fixed build on Linux
Fixed potential crash
Improved documentation of connectionLogger
Fixed #541: returns uid mapping properly
Simplified and fixed implementation of copyMessages (fixes #541)
iOS 7ify the example project
Merge pull request #546 from mronge/master

iOS 7ify the example project
Use ICU of the system (fixed #533)