New app finding on startup; Fix #843

nw will search for app as proposed in #843:

1. search in the end of executable
2. search for manifest in the same directory with executable
3. search for 'package.nw' in the same directory with executable
4. search in the first argument for app
bump version to 0.6.2
Fix 8247d63 for Win
[README] update for 0.6.2
Merge pull request #849 from kingFighter/tests

[test] automatic test case for console.log
[test] update console.log