Updates and Minor Improvements

Updates within this release:

705bddd Update sponge API version to 4.1.0
826609d Update nuvotifer to 2.3.3
0eca96b Fix null file vote cache issues
f767387 Implement constant-time comparison
8ae3c21 Read key with UTF8 encoding
be1c056 Try fixing onlineServer forwarding again
500142e add validation
1e5876b Use try-finally
9355d60 fix #7
700db6d Add standalone server support
f61ba7a fix depend
fe7e8ce SpongeAPI 4.x
7cda39a fix travis
b377a53 Fix vote detection