showall not working correctly for BigFloat

[dpsanders]

julia> a = DecoratedInterval(big(2), big(3), com)
[2, 3]₂₅₆

julia> showall(a)  # wrong
[2, 3]₂₅₆

julia> displaymode(format=:midpoint)  # wrong

julia> a
nothing

format=:full is "correct":

julia> a
DecoratedInterval(Interval(2.000000000000000000000000000000000000000000000000000000000000000000000000000000, 3.000000000000000000000000000000000000000000000000000000000000000000000000000000), com)

However, it does not have the desired effect of being able to copy and paste this into the REPL.
This would require the output to have big"2.000000000000000000000000000000000000000000000000000000000000000000000000000000"

[dpsanders]

This is mostly fixed in #146.
Currently get

DecoratedInterval(Interval(2.000000000000000000000000000000000000000000000000000000000000000000000000000000, 3.000000000000000000000000000000000000000000000000000000000000000000000000000000)₂₅₆, com)

which is not copyable-and-pastable due to the subscript 256.

We need a way to make a BigFloat with a given precision in Julia.

[dpsanders]

Fixed by #210.