lager:
* It is now possible to change the loglevel.
* Log rotation is now supported as well.
p1_logger:
* When rotating a log file, add suffix ".0" to the renamed file.
This is needed in order to be consistent with lager
rotation mechanism.
Use dynamic Rebar configuration
Make iconv dependency optional
Disable transient_supervisors compile option
Add hipe compilation support
Only compile ibrowse and lhttpc when needed
Make it possible to generate an OTP application release
Add --enable-debug compile option
Add --enable-all compiler option
Add --enable-tools configure option
Add --with-erlang configure option.
Add --enable-erlang-version-check configure option.
Add lager support
Improve the test suite
