v1.2.0

CHANGES:

• add LZO support (@dinosaure, @cfcs, @XVilka, #82)
• update binaries (@dinosaure, @XVilka, #89)
• fix an exception leak (@dinosaure, @b1gtang, #88)
• update README.md (@dinosaure, @XVilka, #87)
• fix a mis-use of Zl API (@dinosaure, #85)
• add dune as a dependency of rfc1951 (@dinosaure, @kit-ty-kate, #84)
• real non-blocking state with Zl (@dinosaure, #84)