TextMate can display ellipses ('…', a single glyph with three dots, also known as 'horizontal ellipses') correctly when opening files with them, and when they are typed, but will replace them with '‚Ķ' (not including the single quotes) when saving files. When they are opened again '‚Ķ' will displayed in their place.
Happens with UTF-8 encoding, have not tested other encodings.
System information:
OSX El Capitan Version 10.11 (15A284) MacBook Pro (17-inch, Mid 2010) Processor: 2.66 GHz Intel Core i7 Memory: 8 GB 1067 MHz DDR3 Startup Disk: Macintosh HD Graphics: NVIDIA GeForce GT 330M 512 MB