Add partial test for 'buildExpressionParser'

for multiple left associative operators
Add partial test for 'buildExpressionParser'

for mixed operators
Refine internal function 'rightAssocParser1'

By the way, the function’s name is correct?
Modify format

Just added empty lines
Refine internal function 'leftAssocParser1'
Change names of internal functions
Release v1.1.0