New SHS solver features.
a. Added recognition for MWings/Rings type
designations, as defined in RonK's thread here:
b. Added a “Wings and Rings” checkbox to
specifically look for W and M Rings and Wings
c. You can also list all elimination paths for any step
in the solution path. Here is an example listing with a breakdown of
possible eliminations for step 6 in the solution path.
1. [47.106..] path[2] Hidden Pair, Column.
r12c4<>4, r12c4<>6
2. [47.102..] path[2] Skyscraper, Columns.
r1c6<>4, r3c1<>4
3. [47.100..] path[2] Skyscraper, Columns,
dualends. r1c6<>6, r3c1<>6
5. [48.94..] path[2] Finned XWing, Rows.
r8c7<>3
6.
[48.93.r]
XYWing
=> r1c89<>6 
Find/Apply/Solve?

(1)
XYWing
=>
r1c89<>6
 (2) Discontinuous Nice Loop =>
r1c9<>6
 (3) One AHS Chain, grouped => r1c9<>6
 (4) Discontinuous Nice Loop =>
r1c9<>6
 (5) MRing, type A => r2c1<>7,
r8c2<>6
 (6) ALC2 ColumnBox (MRing C). => r2c1<>7,
r8c2<>6
 (7) MRing, type B, grouped => r2c1<>7,
r8c2<>6
 (8) MRing, type B => r2c1<>7,
r8c2<>6
 (9) XCycle (loop) => r2c79<>4
 (10) XChain => r2c79<>4
 (11) XChain => r2c79<>4
 (12) MWing, type 3B, grouped => r2c7<>6
 (13) WWing, dualends => r2c7<>6,
r8c6<>6
 (14) MWing, type 2B, dualends => r2c7<>6,
r8c6<>6
 (15) Discontinuous Nice Loop => r8c2<>6
 (16) MWing, type 4A => r8c6<>6
 (17) WWing => r8c6<>6
 (18) ALC2 BoxColumn (MRing D). => r2c1<>7,
r8c2<>6
7. [48.91.r] path[3] WWing, dualends.
r2c7<>6, r8c6<>6
8. [48.89.r] path[3] MWing, type 3A,
grouped. r9c8<>6
9. [48.88.r] path[3] XCycle (loop). r2c79<>4
