Array support in formula

Evaluates arrays in formula. Parses and evaluates 2 indexes for 2d arrays. Closes #6 (closed). Closes #5 (closed).

requested review from @thomas.juerges

assigned to @graziano.scalamera

Not implemented:

• Array constants
• Indexes on expression results

Possible issue:

• print of huge array values in GetAlarmInfo command and eventSummary attribute

mentioned in commit 61df5fe1

merged