Added Opportunity Get-, New-, Update-, Remove- functions

[jakendrick3]

Add Get-, New-, Update-, and Remove- wrappers to various Opportunity actions. List of added functions:

Get-, New-, Update-, Remove- CWMOpportunity Get-, New-, Update-, Remove- CWMOpportunityForecast Get-, New-, Update-, Remove- CWMOpportunityForecastItem Get-CWMOpportunityStages Get-CWMOpportunityStatuses