Revert "Trimmed the branch to only the 3rdparty/libsiftfast sub directory"

This reverts commit 2702f258adfec7c9616585422e49e2897b2a3a98.
Rebase from 'upstream'
Trimmed the branch to only the 3rdparty/libsiftfast sub directory
Revert "Trimmed the branch to only the 3rdparty/libsiftfast sub directory"

This reverts commit 00b673d160603a76900f1fed5501fe78b34c9c38.
Rebase from 'upstream' (no changes)
Trimmed the branch to only the 3rdparty/libsiftfast sub directory