HumanReadableNumber(): Simplify output for simple numbers. Examples: (#291)

* HumanReadableNumber(): Simplify output for simple numbers. Examples:

HumanReadableNumber(    0.0)=      0    ---->         0
HumanReadableNumber(    0.5)=   512m    ---->       0.5
HumanReadableNumber(    0.9)= 921.6m    ---->       0.9
HumanReadableNumber(    1.0)=  1024m    ---->         1
HumanReadableNumber(   1.05)=1075.2m    ---->      1.05
HumanReadableNumber(    1.1)=    1.1    ---->       1.1
HumanReadableNumber(    1.2)=    1.2    ---->       1.2
HumanReadableNumber( 0.0e-1)=      0    ---->         0
HumanReadableNumber( 0.5e-1)=  51.2m    ---->      0.05
HumanReadableNumber( 0.9e-1)= 92.16m    ---->      0.09
HumanReadableNumber( 1.0e-1)= 102.4m    ---->       0.1
HumanReadableNumber(1.05e-1)=107.52m    ---->     0.105
HumanReadableNumber( 1.1e-1)=112.64m    ---->      0.11
HumanReadableNumber( 1.2e-1)=122.88m    ---->      0.12
HumanReadableNumber( 0.0e-3)=      0    ---->         0
HumanReadableNumber( 0.5e-3)=524.288u   ---->   524.288u
HumanReadableNumber( 0.9e-3)=943.718u   ---->   943.718u
HumanReadableNumber( 1.0e-3)=1048.58u   ---->   1048.58u
HumanReadableNumber(1.05e-3)=  1101u    ---->   0.00105
HumanReadableNumber( 1.1e-3)=1.1264m    ---->    0.0011
HumanReadableNumber( 1.2e-3)=1.2288m    ---->    0.0012

* HumanReadableNumber(): change simple printing threshold to 0.01.

* ToExponentAndMantissa(): refactor branch sequence.