feat: vendor GYP and libuv dependencies directly into repository for offline builds

Remove dynamic dependency download during build by checking in libuv source and GYP build tooling. Update .gitignore to exclude intermediate build artifacts from the vendored deps directory, adjust Makefile to remove the now-unnecessary cleanall target and deps folder cleanup, and add the full libuv project tree including its own .gitignore, .mailmap, AUTHORS, CONTRIBUTING.md, ChangeLog, and LICENSE files.

deps/libuv/.gitignore

@@ -0,0 +1,78 @@
+*.swp
+*.[oa]
+*.l[oa]
+*.opensdf
+*.orig
+*.pyc
+*.sdf
+*.suo
+.vs/
+*.VC.db
+*.VC.opendb
+core
+vgcore.*
+.buildstamp
+.dirstamp
+.deps/
+/.libs/
+/aclocal.m4
+/ar-lib
+/autom4te.cache/
+/compile
+/config.guess
+/config.log
+/config.status
+/config.sub
+/configure
+/depcomp
+/install-sh
+/libtool
+/libuv.a
+/libuv.dylib
+/libuv.pc
+/libuv.so
+/ltmain.sh
+/missing
+/test-driver
+Makefile
+Makefile.in
+
+# Generated by gyp for android
+*.target.mk
+
+/out/
+# /build/gyp (We do want to commit GYP in Wren's repo)
+
+/test/.libs/
+/test/run-tests
+/test/run-tests.exe
+/test/run-tests.dSYM
+/test/run-benchmarks
+/test/run-benchmarks.exe
+/test/run-benchmarks.dSYM
+
+*.sln
+*.sln.cache
+*.ncb
+*.vcproj
+*.vcproj*.user
+*.vcxproj
+*.vcxproj.filters
+*.vcxproj.user
+_UpgradeReport_Files/
+UpgradeLog*.XML
+Debug
+Release
+ipch
+
+# sphinx generated files
+/docs/build/
+
+# Clion / IntelliJ project files
+/.idea/
+
+*.xcodeproj
+*.xcworkspace
+
+# make dist output
+libuv-*.tar.*