Fix windows build.

1) Updates pix-engine to 0.7
2) Set screen-mode to 0 on start-up, so the OS doesn't change the screen mode. It seems changing the window size stops the textures from working?!

Author: thejpster

.gitignore

@@ -2,10 +2,6 @@
 # will have compiled files and executables
 /target/
 
-# Remove Cargo.lock from gitignore if creating an executable, leave it for libraries
-# More information here https://doc.rust-lang.org/cargo/guide/cargo-toml-vs-cargo-lock.html
-Cargo.lock
-
 # These are backup files generated by rustfmt
 **/*.rs.bk