Fix handling of images with no alt text
Use a Copy Files build phase to copy public headers

Copy Headers build phases don't work for static libraries with Archive
builds (according to Apple's documentation). Use a Copy Files phase
instead to copy them to the same place in a way that works for Archive
builds.
Add SKIP_INSTALL to the Mac target
Merge pull request #13 from keithduncan/skip-install

Add SKIP_INSTALL to the Mac target
Set the project to use spaces for indentation
Merge branch 'master' into github-flavored-markdown
Fix indentation issues (Thanks Xcode!)