tweaked formatting of makeImplicit
fixed type in makeFurtherVector
fixed formatting bug in integration by substitution
fixed bug in parallel/perpendicular lines

When asking for a line parallel to a line of the form y=constant, we only need to return one form of the equation.
fixed bug in par/perp questions where you could get a +1y coefficient
fixed wording of circle/line intersection questions
answers in mathmo are hidden when you press the next/prev buttons
tidied up formatting of ODEs question
fixed stray comma in makeVectorEq
matrices with fractional entries have the fraction factored outside the matrix
tidying up
fixed spacing on revolution problems
corrects spacing in revolutions for fractions
full sentences for stationary points
fixed spacing on revolution figures for fractions
Merge pull request #29 from alexwlchan/master

minor typo tweaks from the laundry list