Remove ':' at end of section headings

A heading is a heading even without a trailing colon.  Maybe the colons were a rest from a time when these weren't normal headings, but some sort of boldface at the start of a paragram...

chapters/derivationofstream.tex

@@ -150,11 +150,11 @@ \section{Rationale for the formulation of \lstinline!inStream!}\doublelabel{rati
 \end{equation*}
 
 \section{Special cases covered by \lstinline!inStream! definition}\doublelabel{special-cases-covered-by-the-instream-operator-definition}
-\subsection{Stream connector is not connected ($N = 1$):}\doublelabel{stream-connector-is-not-connected-n-1}
+\subsection{Stream connector is not connected ($N = 1$)}\doublelabel{stream-connector-is-not-connected-n-1}
 For this case, the return value of \lstinline!inStream! is arbitrary.
 Therefore, it is set to the outflow value.
 
-\subsection{Connection of 2 stream connectors, one to one connections ($N = 2$):}\doublelabel{connection-of-2-stream-connectors-one-to-one-connections-n-2}
+\subsection{Connection of 2 stream connectors, one to one connections ($N = 2$)}\doublelabel{connection-of-2-stream-connectors-one-to-one-connections-n-2}
 
 \begin{align*}
 \text{\lstinline!inStream!}(h_{outflow,1}) &= \frac{\text{max}(-\dot{m}_2,0)h_{outflow,2}}{\text{max}(-\dot{m}_2,0)}=h_{outflow,2}\\
@@ -167,7 +167,7 @@ \subsection{Connection of 2 stream connectors, one to one connections ($N = 2$):
 simplifications of the form $a * b / a = b$ must be provided, or that this
 case is treated directly.
 
-\subsection{Connection of 3 stream connectors where one mass flow rate is identical to zero:}\doublelabel{connection-of-3-stream-connectors-where-one-mass-flow-rate-is-identical-to-zero-n-3-and}
+\subsection{Connection of 3 stream connectors where one mass flow rate is identical to zero}\doublelabel{connection-of-3-stream-connectors-where-one-mass-flow-rate-is-identical-to-zero-n-3-and}
 The case where N=3 and $\dot{m}_3=0$ occurs when a one-port sensor (like a temperature sensor) is
 connected to two connected components. For the sensor, the min attribute
 of the mass flow rate should be set to zero (no fluid exiting the