Probe Path for Preinstalled Executables
Probe Path for Preinstalled Executables

- Change path checks for git, cmake, python and gnuwin32 to warnings
so that users do not have to specify paths if they are already on the
path.
- Add IsOnPath to check for git.exe, cmake.exe, python.exe and gnuwin32
tools and only add new paths if the exes aren't already on the path.

mmitche/llilc,mmitche/llilc,libengu/llilc,pgavlin/llilc,BruceForstall/llilc,dkorolev/llilc,russellhadley/llilc,pgavlin/llilc,JosephTremoulet/llilc,richardlford/llilc,dotnet/llilc,adiaaida/llilc,russellhadley/llilc,russellhadley/llilc-original,dotnet/llilc,tempbottle/llilc,kyulee1/llilcjit,erozenfeld/llilc,dkorolev/llilc,BruceForstall/llilc,AndyAyersMS/llilc,marksantos/llilc,adiaaida/llilc,adiaaida/llilc,russellhadley/llilc,mmitche/llilc,mmitche/llilc,dotnet/llilc,JosephTremoulet/llilc,erozenfeld/llilc,russellhadley/llilc-original,richardlford/llilc,dkorolev/llilc,swaroop-sridhar/llilc,kyulee1/llilcjit,BruceForstall/llilc,tempbottle/llilc,JosephTremoulet/llilc,manu-silicon/llilc,marksantos/llilc,erozenfeld/llilc,erozenfeld/llilc,marksantos/llilc,manu-silicon/llilc,libengu/llilc,russellhadley/llilc-original,libengu/llilc,manu-silicon/llilc,swaroop-sridhar/llilc,AndyAyersMS/llilc,tempbottle/llilc,AndyAyersMS/llilc,russellhadley/llilc-original,swaroop-sridhar/llilc,kyulee1/llilcjit,libengu/llilc,pgavlin/llilc,richardlford/llilc