groomdata: Create recession markers
In greegreg/AdvancedR: Extract and Manipulate Macroeconomic Data

This function requires two dataframes as input. With the input this function trims the B dataframe to the same start date as the A dataframe.

1	groomdata(A, B, level)

`A`	is a dataframe of macroeconomic data created by the ME_dtaextract function and has be trimmed using the ME_growth function (or not).
`B`	is a dataframe created by the ME_Rec function.
`level`	is a logical variable specifying if the level data should be matched to the recession data or if the growth rate data should be matched to the recession data.