Correctly escape single quote.

[smira]

Replace ' with \(cq, as \' is different symbol. See smira/aptly#22 and #21.

[ghost]

@rtomayko Would you please check this PR and merge?

[alkisg]

We're also affected by this; we're using Ronn to generate ltsp.org man pages from markdown, and when we have a line like sed 's/one/two/', Ronn converts it to sed ´s/one/two/´, and users complain about syntax errors in man pages.

[alkisg]

Hmm actually (cq isn't appropriate; this renders as RIGHT SINGLE QUOTATION MARK' (U+2019) which is still invalid code.

man ls on the other hand uses plain single quotes, NOT escaped, and they work fine.