added thoughts on operator inheritance
new constraint added for new type Timematr
types and module renamed, new types created
new type timematr
getting rid of swappable macros in operators
abstractFunctions holding for all subtypes
added outer constructors for all types
added distinctions of constructors with respect to NAs
files included and new abstract subtype defined
getindex methods in own file, wrapped up with macro
new tests for constraints of Timematr also
display now shows exact subtype
Timedf deleted -> is called Timedata from now on
most of old code outsourced into different files, conversions added
conversions added to timedata
conversions added, old code from Timenum inherited -> Timematr is new Timenum
renamed to AbstractTimedata, operators with ambiguity in comments
read and write functions in separate file - write checks for best subtype
testfile for abstract functions started