Merge pull request #19 from mcg1969/master

VS2013 and later: set NANODBC_USE_CPP11, silence warnings
example.cpp: return 0, or exit(1)

For example to be usable as a simple test, it needs to return
a proper.
example.cpp: check params and show usage

example.cpp needs to validate the parameters passed to it and
show a usage message if the parameters are invalid.
Fixed equals operator for date.
Merge branch 'example-fixes' of https://github.com/reubenhwk/nanodbc into reubenhwk-example-fixes
Some small style related changes.
Cleaning up example code a bit.
Noticed a double space, deleted it.