Fixing improper input syntax and failing bounds check
Use actually valid transactions for script tests
Add actual signature tests
Grammar fixes in README

Github-Pull: #4956
Fixing out of bounds error in GetKey()
Merge pull request #4962

6f3ae9b Fixing out of bounds error in GetKey() (ENikS)
Merge pull request #4949

c8589bf Add actual signature tests (Pieter Wuille)
76ec867 Use actually valid transactions for script tests (Pieter Wuille)
Merge pull request #4955

87314c1 Fixing improper input syntax and failing bounds check (ENikS)
Fixed typo in README.md file. "-regest" "-regtest"

There was a typo in the README.md file. It previously read "-regest" instead of the proper "-regtest" and it has been updated to the proper reading.
Merge pull request #4974

b498a94 Fixed typo in README.md file. "-regest" "-regtest" (Eric Shaw)
[Qt] add more NULL pointer checks in bitcoingui

- add missing checks for clientModel and optionsModel
- small cleanups for an #ifdef on Mac
- remove an unneeded else