#731 DynamicDropdown tactics

[Alex Iliasov]

Proof tactics created via org.eventb.ui.proofTactics/dynamic_dropdown appear to run from Eclipse UI thread thus blocking out platform UI for the time tactic runs. This makes it unappealing for calling external reasoners.

A possible solution is to create model context in DynamicDropdownManager wrapping around a call to applyTactic().

[Alex Iliasov]

oops, "model context" -> "modal context"

[Thomas Muller]

Fixed in revision [efe5f8]. Will be available in Rodin 3.2.