MetaTrader 5 build 3660: Improvements and fixes

Terminal

1. Fixed occasional incorrect platform log creation.
2. Updated translations of the user interface.

1. Fixed checking global variables. When declaring identical variables in different namespaces, the compiler gave an erroneous warning that the variable was already declared.
   

Web Terminal

1. Added user interface translation into Portuguese. The web terminal is now available in 12 languages.
2. Fixed the dialog for adding Standard Deviation indicator.
3. Minor fixes and improvements.