* Modernize Build Scripts
* Fix: Missing dot at extension file name.
Reported by @FortyTwoFortyTwo
* Clean Up: Removed unused variable
* Copying No Longer Needed
Copying the HL2SDK manifest is no longer needed.
Requires latest AMBuild.
* Allow Using Manifests From Project Folder
Check if the manifest already exists in the project folder. If not, then search in the path specified by --hl2sdk-manifest-path.
* Requested Changes by Kenzzer
* Fix Differences Between SDK/No SDK
* Update MM:S version in CI, dependency checkout scripts and sample extensions
* Update MM:S version in CI, dependency checkout scripts and sample extensions
* Fix EOL problems
* Initial PVKII branch support
* Change PVKII code to 23, DOTA uses 22 in MM
* Bunch more SE_PVKII preprocessor that was missed
* Add some missing SOURCE_ENGINE_PVKII cases
* Update PVKII FireOutput signature for Linux
* Update checkout-deps with 'pvkii'
* Fix FireOutput signature for PVKII, accidentally used one from newer build
* Change PVKII code to 10, and bump others by 1
* Only check against SE_SDK2013 here, like Metamod
* More SE_PVKII preprocessor cleanup
