reworked assertions in tests to be more informative
fixed bug where array modifications weren't returned due to non-pointer usage in loop
fixed remaining bugs in DiffCharsToLines
fixed bug in reverse overlap elimination - added pretty printing for diff sets in tests
fixed DiffFromDelta bug where byte slicing was used instead of rune slicing
Changes 'deadline' to be int64 instead of int32

The test used the year 9999 when calling DiffBisect. int32 can only go
up to about the year 2038, thus the date being used could not fit in an
int32, but does fit in an int64.
removed TODO form DiffBisect lines because they are done
concat function is not needed, builtin append works in place
fixed bug in my diffMain refactor and fixed diffCompute bug where DiffInsert was used instead of DiffDelete
added int min function. Improved pretty test fail output for assertDiffEqual. Cleaned up diffCompute func
Added a New function that creates a default DiffMatchPatch
fixed a bug in DiffBisect wrt runes vs bytes
go fmt
switched to a different assert package
fixed bug due to rounding/float/int conversion
deadline is now time.Time.  Fixed timeout bug wrt seconds vs 1000*seconds.
fixed var shadowing bug in diffLineMode
added type-safe wrapper DiffMain around private diffMain - no more interface{} args. max int from math package.
used utf8 decoderuneinstring funcs for forward/reverse range rather than rune conversion - all funcs take only string args now
cleaned up func args. Fixed uninitialized bisect slices