trx_toolkit: introduce logging configuration arguments
Before this change, it was impossible to configure logging
parameters from command line, such as log level and format.
This change introduces the following optional arguments:
--log-level - logging level for stderr (by default, DEBUG);
--log-format - logging message format for stderr;
--log-file-name - enable logging to a given file;
--log-file-level - logging level for file (by default, DEBUG);
--log-file-format - logging message format for file;
which are defined in a new class called ApplicationBase, so
all existing applications should inherit them now.
Change-Id: Ic3b0440cd73946ad444bd7e48feb7a92d45f6488