7/cs-pointers: mv svg/ -> res/

We'll generate pdfs too.
7/cs-pointers/res: generate *.pdf from *.svg

PDFs can be included easily in a TeX document.  Additionally, make the
following changes:
* Make .gitignore ignore only /*.pdf, not *.pdf in general
* Update the paths in draft.tex from png/*.png -> res/*.pdf.
7/cs-pointers, 9/curve-fitting: update .gitignore
7/cs-pointers, 9/curve-fitting: add Makefile

It's just a simple rule to execute `pdflatex`.