dev/core#443 Fix Non-static method calls at CRM_Utils_Mail_Incoming

[scardinius]

Overview

Strict warnings occurs at PHP7.1

Before

Some methods are declared as non-static but used as static

After

Declare methods with proper access modifier

[civibot]

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[mattwire]

@scardinius I agree with all the changes. They are all static functions called by the same class. However what about formatUnrecognisedPart() and &parse()? I'm pretty sure they should be static too (and the function by reference (&parse) should be dropped in favour of parse() as that was a PHP4 construct.

[eileenmcnaughton]

@mattwire raises some good points about some additional changes worth making - but they are non-blocking IMHO as these changes are correct & worth merging. Merging as fails are unrelated