Extend B23MuNu to B23ellnu

I also loosened the cuts on B23MuNu a bit to improve the sensitivity.

StrippingReport                                                INFO Event 20000, Good event 20000
 |                                              *Decision name*|*Rate,%*|*Accepted*| *Mult*|*ms/evt*|
 |!StrippingB23MuNu_TriMuLine_TIMING                           |  0.0150|         3|  1.000|   0.081|
 |!StrippingB23MuNu_TrieLine_TIMING                            |  0.0400|         8|  1.000|   0.073|
 |!StrippingB23MuNu_MueeLine_TIMING                            |  0.0200|         4|  1.000|   0.060|
 |!StrippingB23MuNu_MuMueLine_TIMING                           |  0.0150|         3|  1.000|   0.062|
 |!StrippingB23MuNu_TriFakeMuLine_TIMING                       |  0.0150|         3|  1.667|   0.041|
 |!StrippingB23MuNu_TrieFakeLine_TIMING                        |  0.0050|         1|  1.000|   0.040|
 |!StrippingB23MuNu_MuMueFakeLine_TIMING                       |  0.0200|         4|  1.500|   0.059|
 |!StrippingB23MuNu_MueeFakeLine_TIMING                        |  0.0000|         0|  0.000|   0.026|