Refresh examples

[plicease]

Big Example Refresh PR

This is for #383 but we will also hopefully touch on other documentation PRs as we work on this.

Order

• The examples should be reordered from least to most complicated, finishing with a full dist example. Some of the examples are already appropriately placed, but some are totally wrong.
• Integer example
• String argument example
• String return example (possibly more than one, owned, unowned, static, etc)
• Pointers
• Opaque (objects)
• Opaques (malloc/free, buffers, strdup)
• Arrays
• Pointers as arrays
• Unix GUI (libnotify)
• Windows GUI (MessageBoxW)
• FFI::C
• Record
• Buffers (FFI::Platypus::Buffer)
• Window (FFI::Platypus::Buffer::window)
• OO opaque (libarchive)
• OO integer (unix open)
• variadic functions (libcurl)
• Callback
• Bundle code

Format

• New format: each example should include these sections (some are optional):

1. C API (for external libraries) this can be a link to the appropriate documentation
2. C Source (for bundled examples)
3. Perl Source
4. Execute
5. Discussion

Pictures

• GUI stuff should have images in the HTML. This should live in the Execute section. In think there are only two examples so far:
• libnotify
• MessageBoxW

Rework stuff removed in these refactors

• Using FFI::CheckLib to find libraries
• Renaming functions when attaching
• use of function vs. attach (this should maybe go into the varadic / curl example)
• using wrappers

Testing

• examples should be easily tested
• using prove
• and CI
• examples that cannot easily be tested in at least CI should be removed (possibly exception: GUI examples)