[squash] Added asynch posix version of io layer

    * [feature] Should declare values as const
    * [async][fix] Logic and yield before reading
    * [git][fix] added the generic rule to qt generated files
    * [feature] Adding POSIX asynch layer
    * [fix] updated the nob version of functions
    * [wip] non blocking asynch posix reference version
        Conflicts:
                Makefile.include
    * [wip] asynch version of datastream get
    * [fix] problems with asynch data reading
    * [examples] Add missng `<sys/select.h>`
    * [fix] compilation warning and make it to not compile if nob is disabled
    * [buid] added setting of the nob flag for examples
    * [build] updated build scripts in order to build asynch version without conflicts
    * [build] Should enable non-blocking wrapper automatically
        Conflicts:
                Makefile.include
    * [fix] added missing non blocking version
    * [fix] added checking for the case where data send and received correctly
    * [feature] added example of usage xively in a loop
    * [refac] used the feed_get_all in asynch examples
    * [feat] added test of asynchronious feed update
    * [tidy] cleaned examples and made them usable even if xively not compiled against asynchronious settings
    * [fix] post cherry-pick fixes
[fix] compilation errors & warnings
[fix] added parsing of payload in case of http status != OK
Merge pull request #91 from xively/feat-add-non-blocking-functionality

[squash] Added asynch posix version of io layer