Minor textual improvements to README
[chapter_00] using the imperative for consistency with rest of document
[chapter_00] Removing repeated "Then" sentence beginning
[chapter_01] using "into an entire" instead of "to an entire"

... and wrapping the text to 80 chars width after the change
[chapter_01] point -> pointer
[chapter_01] splitting a sentence into two

This reads a bit better as it separates the two (related) ideas in the
paragraph.
[chapter_02] using infinitive instead of present continuous

For some reason this reads better to my anglophone ears...
[chapter_02] rewording chromaprint introductory sentence

This is because I got tripped up on the first reading of the sentence at
"with called" and this version is shorter and seems to read better.
[chapter_02] noting that the XS code needs to be added to XSFun.xs
[chapter_02] adding parens to get_version

Now XS is able to find the function signature correctly
[chapter_02] adding perl shebang line

This is then consistent with chapter_01
[chapter_02] reminding the user to export the function
[chapter_03] correcting a plural
[chapter_03] using lower case for "object oriented" within text sections
[chapter_03] minor changes to textual flow
[chapter_03] "make install" should really be "make test"
Merge remote-tracking branch 'paultcochrane/ptc/docu_fixups'