This adds an experimental directory which contains various
experimental algorithms and functions. The files and APIs
under this directory are experimental and unstable.
This changes the vector<T> constructors which copy or initialize
data to take a queue argument used for performing the operations.
Previously they just took a context argument used to initialize the
buffer and then created a new command queue to use. This improves
performance by not requiring a new command queue and also fixes issues
when performing operations on a different command queue while the
vector was still being initialized.
This adds a sort_by_transform() algorithm which sorts a sets of
values based on the value of a transform function.
For example, this can be used to sort a set of vectors by their
length (when used with the length<T>() function) or by a single
component (when used with the get<N>() function).
