• allow merge for display property (#167, #244)
• more accurate rect (clip property value) merge
• fix typo when specifying options in cli (thanks to @Taritsyn)
• fix safe unit values merge with keyword values (#244)
• fix wrong descendant combinator removal (#246)
• build browser version on prepublish (thanks to @silentroach)
• parser: store whitespaces as single token (performance and reduce memory consumption)