Added FolderExists, FileExists, and ReadTextFile functions

Function FolderExists(strPath) As Boolean
'Checks for the existance of a folder referenced by strPath

Function FileExists(FileName As String) As Boolean
'Checks for the existance of a file referenced by FileName

Function ReadTextFile(Fname As String, Length As Integer) As Variant
Merge pull request #1 from boyddensmore/master

Added FolderExists, FileExists, and ReadTextFile functions