Loosening lower B mass cut in B2XMuMu + Using VeryLooseKsLL container in S29r2p1

Loosening the cut will improve the control over the tails in the K*->K+pi0 channel. Has already been done in S28 (see !629 (diffs))

The StdVeryLooseKsLL container increases the number of KsLL candidates by roughly 50%

Rates stay well below 0.5% (see below)

StrippingReport                        INFO Event 10000, Good event 10000
 |                     *Decision name*|*Rate,%*|*Accepted*| *Mult*|*ms/evt*|
 |_StrippingGlobal_                   |  0.3200|        32|       |  11.415|
 |_StrippingSequenceStreamLeptonic_   |  0.3200|        32|       |  11.018|
 |!StrippingB2XMuMu_Line              |  0.3200|        32|  6.156|   9.580|
 |!StrippingB2XMuMu_Line_TIMING       |  0.3100|        31|  6.355|   0.133|