Migrate to mkdocs

See merge request !84

update time function in real time src

See merge request !83

qol

See merge request !82

fix bug where adapter doesn't check for discont when all buffers are flushed out

See merge request !81

update TransformElement source pad method name

See merge request !79

Simple way to reuse the docstrings defined in the base class.  The method
docstrings don't need to be updated, as the overall class docstring should
describe what the element does.

See sgn!55

allow specifying PYTHONPATH for makefile test target

See merge request !74

remove internal pad

See merge request !80

fix missed uses of numpy.concat

See merge request !78

minor tweak to Frame reprs

See merge request !77

add commas for buffer list elements

better repr for EventFrame and TSFrame

See merge request !73

use numpy.concatenate instead of concat

See merge request !76

TSSource: use None instead of floats for default time values

See merge request !71

add Amplify element

See merge request !72

the concat alias is not supported in versions before 2.0.

Don't neglect to include the rest of the frame attributes.

t0 = 0 corresponds to an actual time, which is conceptually different
from an unspecified time, and some source elements may need to behave
differently for unspecified times.

For consistency we make the same default change for "end" as well.

improvements to TSSource support methods

See merge request !67

add sgn event classes

See merge request !70

the name "channels" is a bit confusing, where as "sample_shape" seems to
be a more accurately descriptive name.

The logic here is that this function works on pads, setting the attributes
associated with a pad, so the pad is actually the primary argument of the
function and should therefor be the first argument.

to confirm to more standard single line summary, followed by more
detailed description.

and fix imports in resampler