Changed null values to Empty
New
Added getFileList()
Added file reference
New
Added file reference to TeXSyntaxException
Added file reference to TeXSyntaxException
Added file reference to TeXSyntaxException
Added getFile()
Added reference to LaTeXSyntaxException
Made includegraphics abstract; added LaTeXFile
Added getFileName()
Added includegraphics and getFile
Added getFile()
Added file reference to TeXSyntaxException
Added file reference to TeXSyntaxException