Merge pull request #134 from BugFreeSoftware/Rebase_fixes

Windows bugfixes after rebase:
Remove unnecessary concat() function usage
Replace OTAPI_Wrap::Output with OTLog streams
Replace print() with cout stream
Removed useless VerifyIntVal, VerifyTimeVal and VerifyBoolVal
(artifacts of Chai to C++ conversion)
This exposed a potential bug in OTAPI_Exec::Instrmnt_GetAmount and
OTAPI_Exec::Transaction_GetAmount where -1 was used for failure
(artifact of converting amounts from string to int64_t)
Removed useless comments from ot_commands_ot.cpp
A few small refactorings/corrections
Replaced use of OTCleanup with unique_ptr
Simplified error message for missing parameters
Removed useless VerifyNotNull, VerifyStorable and VerifyType functions
(Chai to C++ artifacts)
Replaced bContinue construct with continue statement.
(Chai to C++ artifact)