Led pin connection issues bugfix

[rinon13]

Minor bug still required to fix: "LED is not Connected properly" shown once when Start Simulation is pressed. Shown only when pins of LED are connected to digital pins of Arduino.
Edits:

• Commit 7fb133a: Error message issue fixed but will only check if pins of LED are properly connected. Will not check for logic issues.
• Commit 0681b79: LED now works when other components (e.g Resistor) is connected in between when connected with only digital pins of Arduino.

Bug fixes for Issues: #192 , #469 and #470