Keep (un-deprecate) `read_table()` for API stability
#### Problem description
`read_table()` got deprecated in favour of using `read_csv()`.

Using `read_csv()` to read tab/space delimited files is counter-intuitive. According to the docs and the related issues, both share the same code and it is not clear why the one function should be preferred over the other, and that change may even break existing code.

In my point of view `read_table()` is the more general function and `read_csv()` is a special case. Why would you deprecate (and then remove) the more useful function? It is already annoying to use `to_csv()` to write space/tab delimited files. And as I can see it, it comes down to two lines of code.

#### Proposed solution
Keep both functions as they are (un-deprecate `read_table()`) or rename the function to have a more general name like `read_txt()` (as in `numpy.genfromtxt()`) or similar.