* Enforce validators can only use the correct pubkey type
* adapt to variable renames
* Address comments from #2636
* separate updating and validation logic
* update spec
* Add test case for TestStringSliceEqual, clarify slice copying code
* Address @ebuchman's comments
* Split up testing validator update execution, and its validation
These functions were not used anywhere within tendermint, or the
cosmos-sdk. (The functionality is already duplicated in the cosmos-sdk
types package)
* common: Delete unused functions within byteslice
* remove more unused code from strings.go and int.go
* Remove more unused code from int.go
* Fix testcase
