Review: std.logger

[Dicebot via Digitalmars-d]

Round of a formal review before proceeding to voting. Subject for 
Phobos inclusion : http://wiki.dlang.org/Review/std.logger 
authored by Robert Schadek.

Code:
     https://github.com/D-Programming-Language/phobos/pull/1500
Documentation:
     
http://burner.github.io/phobos/phobos-prerelease/std_logger_core.html
     
http://burner.github.io/phobos/phobos-prerelease/std_logger_stdiologger.html
     
http://burner.github.io/phobos/phobos-prerelease/std_logger_filelogger.html
     
http://burner.github.io/phobos/phobos-prerelease/std_logger_multilogger.html
     
http://burner.github.io/phobos/phobos-prerelease/std_logger_nulllogger.html
     
http://burner.github.io/phobos/phobos-prerelease/std_logger_templatelogger.html
DUB package:
     http://code.dlang.org/packages/logger

Previous discussion thread:
     
http://forum.dlang.org/post/mailman.313.1377180809.1719.digitalmars-d@puremagic.com

======================================================================

Summary of changes since last discussion (by Robert):


* logger is now a package of multiple files
* a lot more documentation
* log and logf now behave as their write and writef counterparts
* for logging with an explicit LogLevel call logl loglf
* for logging with an explicit condition call logc logcf
* for logging with an explicit LogLevel and explicit condition 
call
loglc loglcf
* the log function with an explicit LogLevel like info, warning, 
... can
be extended into c, f or cf and therefore require a condition 
and/or are
printf functions
* unittest have been updated
* dub package for easy testing

======================================================================

This is one of long sanding Phobos candidates Robert has put some 
great effort into. As far as I know it is already used in several 
D projects and it is a good moment to make it official.

Review goals, as usual : verify that API is robust enough to 
build more complicated logging systems on top of it, verify 
Phobos style compatibility, check if provided documentation is 
complete and friendly enough.

Base for review process is defined by 
http://wiki.dlang.org/Review/Process