MongooseIM 1.5.1

This release includes:

• fix for bosh inactivity timeout (#341)
• improved compatibility with Stanza.io - including also fix for stream management (#347)
• removed dead code (#328, #335, #336, #339)
• unified roster logic (#359)
• rearranged documentation (#363, #368)
• other small improvements ( #337, #338, #345, #349, #350, #353, #364, #366)
• complete list of merged PRs
• complete list of closed issues