I'm sure you're looking for a simple tool, but mine is NetBeans 8.
It's a free editor that supports all formats and uploads files over sftp whenever they are changed (internally or externally).
I extensively use copy/paste history, refactoring, auto-completion, git support, file history view...
Make sure you have the Oracle release of Java otherwise you'll face issues.
Useful shortcuts
alt left/right: jumps to previous/next places you were at
ctrl q: jump to previous places you modified
ctrl b: jump to declaration
ctrl g: go to line number
ctrl p: show function parameter declaration from a function call
ctrl shift space: show php library function full documentation
ctrl shift d: show last 9 copied text even if the text was copied from outside NetBeans. click or type 0..9 to paste
ctrl f: search for selection; F3 for next, shift F3 for previous; +shift = whole project
ctrl h: replace selection; +shift = whole project
ctrl /: comment one or more lines; +shift = opposite effect
tab: add a tabulation to all selected lines; +shift = opposite effect
ctrl shift v: paste and format so it's well indented
ctrl shift s: save all project files