1. remove unused functions in deploy code

for example - ExecuteProgram in src/common/windows/native/RegCommon.cpp

2. use common pattern to create process where possible

there's a lot of places with duplicated code:

 - creating STARTUPINFO, PROCESS_INFORMATION structures
 - calling CreateProcess, WaitForSingleObject
 - closing handles

and actually there are several existing functions in deploy code

 - ExecuteProgram in src/common/windows/native/RegCommon.cpp
 - ExecCommand/ExecCommandEx in src/common/windows/native/common.h
 - StartProcess in src/common/windows/native/UpdateConf.cpp

it should be one function in common.h and we should use it in deploy code consistently

3. consider getting rid of CreateProcess and use "safe" ShellExecuteEx where possible

4. Runtime.exec(String) isn't recommended way to execute command - consider using ProcessBuilder