YCMEPHelper: Mark YCM_EP_EXPERT_MODE and YCM_EP_MAINTAINER_MODE as advanced
YCMInternal: Fix typos in variable name
YCMInternal: Fix path handling after testing on Windows
YCMInternal: Fix install destination
Add .mailmap file
Properly handle CMake files installation dirs
On multi-config generators always build in "Release" configuration
Generate documentation