Support custom text editor to modify scripts

[qgib]

Author Name: Mikhail Titov (Mikhail Titov)
Original Redmine Issue: 12365

Redmine category:processing/core
Assignee: Victor Olaya

---

I would really like to see my R scripts edited in, e.g., Emacs, for this emacsclientw shall be called with the name of the script file.

One way would be to respect EDITOR environment variable and just let Windows users know to set it up (and how) for an alternative editor to be used. On the second thought, OSGeo4W really messes up environment variables.
Or just add an explicit option to select an editor.

[qgib]

Author Name: Alexander Bruy (@alexbruy)

---

• category_id was changed from 124 to 94

[qgib]

Author Name: Giovanni Manghi (@gioman)

---

• category_id was changed from 94 to Processing/Core

[qgib]

Author Name: Giovanni Manghi (@gioman)

---

• easy_fix was configured as 0