update global_ignore for vim's swap files

https://github.com/github/gitignore/blob/464ae2642b5fbee2528c24daa922e5ebef7c3c4c/Global/vim.gitignore
change notation 'a/**' to 'a/'
track .project and .classpath for eclipse projects
ignore .gradle
add global_ignore rules for source code tag systems

https://github.com/github/gitignore/blob/master/Global/Tags.gitignore
Merge branch 'grow_global_ignore'