last hack time and captured time info in portal info dialog

Additional stuff in portal info dialog: time since portal capture and time since last hack. Times are displayed in shortened format, like "10m23s" or "1h12m", showing only most significant time part and one below. Hack times are not forgotten. There is no data export for hack times, which are kept in private app file.
Issues:
- adds [mod] tab switch for displaying time since last hack but not for portal capture (inconsistency)
- due too limited vertical space on portal info dialog, if both capture time and hack time are to be displayed, info is abbreviated to something like "C:XmYs H:ZhVm" to keep it in one line (more work needed to properly display this info), if only portal capture time is to be displayed it looks like "Capt.:XmYs" ("Hack.:XsYm" if only hack times is to be displayed)