title: Git rewind master branch to specific commit in master's history
body: <p>I have the following recent history in my git repo.</p>
  
  <pre><code>* 7661a06 (HEAD, origin/devConsolidate, devConsolidate) Fix seg fault; OCBA intermediary compares by value() now also
  | * 0bbe038 (origin/master, master) Flawed work no seedShift
  |/  
  * 62fe9db Turn on OCBA_DEBUG; nan/inf values in OCBA prior to crash
  * 71298c8 Turn on OCBA (non-intermediary); seg fault occurs
  * 3693904 No OpenMP, no OCBA; no memory leaks on valgrind
  * 9d5686c Disable OpenMP threads
  * 80bbc3b Debug (-O0) build now throws exception also
  * e148013 Post convert simulation4_NEJMdisutilities [] to at()
  * 66cfba9 Post convert OCBA [] to at()
  * 32db3be Pre convert OCBA [] to at()
  * 4a9f25b Prep for debugging
  * 907e88b Found error (vector out of bounds); need to fix from here
  * ca6c639 Implement elapsed, iteration, and max time in OCBA
  * db68c15 Fix SEG FAULT; OCBA now working (with intermediary)
  * f1c6f05 GA now uses OCBA; GA/OCBA params from config file; produces SEG FAULT
  | * 3b16dcf (origin/genCRNgraph, genCRNgraph) Generate QALYs test and control independent-sampling
  |/  
  *   001eff2 Merge branch 'OCBAdev'
  </code></pre>
  
  <p>All the commits subsequent to (descendants of) <code>f1c6f05</code> were done to debug a problem.  In hindsight, I should have create a separate branch to do this debugging, but I did it all in <code>master</code>.  Now, in commit <code>7661a06</code>, I have fixed the bug.</p>
  
  <p>I want to move (rewind?) the <code>master</code> branch (or pointer) so that it is located at commit <code>f1c6f05</code>.  After I do this, then I can generate a patch from the diff between commits <code>7661a06</code> and <code>62fe9db</code> and apply it to <code>f1c6f05</code>.  As a result, a portion of my git log should look like this:</p>
  
  <pre><code>* 7661a06 (origin/devConsolidate, devConsolidate) Fix seg fault; OCBA intermediary compares by value() now also
  | * 0bbe038 Flawed work no seedShift
  |/  
  * 62fe9db Turn on OCBA_DEBUG; nan/inf values in OCBA prior to crash
             .
             .        
             .
  * db68c15 Fix SEG FAULT; OCBA now working (with intermediary)
  | * &lt;HASH&gt; (HEAD, origin/master, master) Fix problem and rewind master
  |/
  * f1c6f05 GA now uses OCBA; GA/OCBA params from config file; produces SEG FAULT
  | * 3b16dcf (origin/genCRNgraph, genCRNgraph) Generate QALYs test and control independent-sampling
  |/  
  *   001eff2 Merge branch 'OCBAdev'
  </code></pre>
  
  <p>What commands would I use to achieve all of this?  Specifically, how would I: (1) move master, (2) generate the patch, and (3) apply the patch?</p>