Simplifed conversion (lb/kg) to only use the singular

Corrected decimal alignment display bug

- Adding number without decimal would not align
- Added a test for the new queryDecimalIndex() method
- Updated pom.xml to ignore windows error on `chmod` for
  exec-maven-plugin
- Updated maven exec plugin from 3.3.0 -> 3.4.0
- Updated JUnit from 5.11.0-M2 -> 5.11.0-RC1

Rolled back jLine library update

Getting a JANSI deprecation warning

Added `in2ft` and `ft2in` commands

Added tests for the new converesions
Updated user guide
Updated shade plugin from 3.5.2 -> 3.5.3
Updated jUnit from 5.10.2 -> 5.11.0-M1
Updated jLine from 3.25.1 -> 3.26.1

Code Optimization

Improved command parsing
Updates to userguide export command.  No backslashes!
LR calc optimization
Additional exception processing
Grammer/spelling
Much is based on IntelliJ recommendations

Enhanced linear regression and maven updates

Added the ability to predict a result from a selected X value
Adding next value to stack is no longer the default - you need to use
the `add` parameter
Updated the following plugins:
  maven-compiler-plugin
  maven-surefire-plugin
  maven-shade-plugin
  exec-maven-plugin
Updated the following dependencies:
  fross libray
  jline-reader
  jline-terminal-jansi

Updated UserGuide for the Linear Regression command
Added enhanced lr tests

Added `addall`, `delete`, and `modulus` commands to UserGuide

Bug fixes with fractions

- Entering negative fractions would calculate incorrectly
- Fraction rounding didn't work correctly
- Updated and added tests for fractions
- When rounding, allow for a precions of 0 (no decimals)
- Created a spreadsheet to help with fraction testing
- Removed the silly '0/1' in the fraction display

Allow `mem list` to call `list mem`

I always seems to type this incorrectly, so I'm not going to document it
in the user guide or in-program help, but I'm going to simply remap the
incorrect command to the correct one

Fixed crash on `-+` input & alignment display bug

- If you entered a `+-+` as a command rpncalc would crash.  I've added a
  catch for this and just display an error
- with large scientific notation numbers, the decimal and right
  alignment could be incorrect as it counted every zero in the expanded
  display.  This is now handled correctly.  Root cause was the
  Output.Comma method.