Merge pull request #18 from COMBINE-lab/master

Fixes usage of spdlog in a project that also uses cppformat
 * openlog setup for syslog sink
 * update README example
Add a Makefile to main directory.

It eases the project integration with some IDE applications.
fixed clang make
Added debug macros
Merge branch 'master' of https://github.com/gabime/spdlog
Small fix to example
Optional arguments for syslog_logger factory.
Call closelog in syslog sink's destructor
Remove test- prefix from examples make targets
Merge pull request #20 from fooinha/syslog-openlog

Syslog openlog
fix syslog bug
bench fix
syslog improvments
append instead of truncate when opening new files
some small cleanup and define WIN32_LEAN_AND_MEAN
example update
#undef WIN32_LEAN_AND_MEAN if it was not dedfined before spdlog defined it
undo last commit