Change "process.env['HOME'] " to "os.homedir()"

[mambax7]

For Windows this would not work with 'HOME' as in:
var confFile = process.env['HOME'] + '/.gitall/config.json';

but this should cover all OS cases:

var os = require('os');
var confFile = os.homedir() + '/.gitall/config.json';

the same with:
var logLocation = process.env['HOME'] + '/.gitall/gitall.log';