plugin: srcexpl: update srcexpl to 5.3

Signed-off-by: Danny Huang <dahuang@nvidia.com>
plugin: NERD_tree: add NERD_tree 2.13.0

Signed-off-by: Danny Huang <dahuang@nvidia.com>
plugin: trinity: add trinity 2.1

Signed-off-by: Danny Huang <dahuang@nvidia.com>
vimrc: miniBufExpl: comment out unused key binding

Signed-off-by: Danny Huang <dahuang@nvidia.com>
vimrc: Grep: change key binding to <Leader>f

Signed-off-by: Danny Huang <dahuang@nvidia.com>
vimrc: SrcExpl: Update settings

Signed-off-by: Danny Huang <dahuang@nvidia.com>
vimrc: remove tailing space

Signed-off-by: Danny Huang <dahuang@nvidia.com>