Added am2PInit

Added initialization function for ari
Added ability to specify custom naming function

Can now specify custom naming function as fourth argument to
motionCorrect. namingFunction is a handle to a function for naming. If
empty, uses default naming function which is a local function of
motionCorrect. All naming functions must take in the following arguments
(in  order): obj.acqName, nSlice, nChannel, movNum.
Name objects based on folder structure

Changed initialization code to name objects based on folder structure.
Allow initialization to load files

Initialization will search for previous 2PObject and load if exists.
Merge remote-tracking branch 'origin/master' into ari
Merge remote-tracking branch 'origin/master' into ari
Fixed MJLMSelectROIs
Adapted parseScanimageTiff to work with SI5 #2
Merge branch 'master' of https://github.com/HarveyLab/Acquisition2P_class