Fixes an incorrect example in the VLAD documentation (closes #62)
gmm.h: fixes misspelled function (closes #60)
liop.c: fixes a potential buffer overrun (this was very unlikely if not impossible to happen in practice) (closes #61)
vl_ubcmatch.c: faster (closes #49)
vl_printsize.m: improves behaviour when setting the aspect ratio
covdet.c: improves doc
vl_plotframe.m: improves doc