Release 0.2

Changes since 0.1:

- Can use "make PREFIX=..." to set install prefix.
- libminios has been renamed to libminios-xen (the old .pc file is still
  installed, but will be removed soon).
- Don't include start object twice in library.

ARM:

- The floating-point hardware is now initialised.
- The stack is at the start of RAM, so overflow will cause a fault.
- Extra ELF sections (e.g. .got) are no longer zeroed out.