Major new release - bug-fixes, faster start-up new functions etc

Major release made with quite a bit of help from the Claude A.I.

• Much faster to start on Windows (achieved by delaying the network access used for retrieving currency data and compiling in a single font containing all the required symbols).
• Fixed a couple of crashes when buttons were pressed in a certain order (e.g. backspace after clear)
• Fixed the degrees ↔ DMS conversion, which had a few issues with rounding errors
• Substantial new test suite to ensure that the calculator is as accurate and reliable as possible
• New statically compiled version (a single executable rather than a folder full of DLLs), which is smaller and also seems to start quicker in my tests.
• A couple of new functions: binary shift-left and shift-right. Adding these meant I had to shuffle the keys around a little (RAND is now on the constants page, y^x on the front page and √x is only on the front page rather than duplicated on the functions page). If you want to go back to the old layout there's an option on the second page of options (called "Classic Keypad Layout")

The Android version has also had a major update. If you'd like to see the Android version on the Google Play Store, then please get in touch with me (preferably via https://www.cgtk.co.uk/contact). Google require "at least 12 testers opted-in to your closed test", so if no-one volunteers, I won't be able to release it.

Speed-up start-up on Windows

Improvements (suggested by claude.ai) to make ARPCalc start faster on Windows. The main difference is limiting the number of fonts that Qt scans on start-up (it seems to have previously been scanning every font on the computer).

Fix for US pints to litres conversion

Resolves #1 (an issue with the conversion from US pints).

Fix for mpg/mpl conversion

Conversion between miles per gallon and miles per litre was incorrect in the desktop version. This also affected several other conversions involving fuel economy. Android version was correct so has not been updated.

Minor bugfix related to storing variables

Storing variables in upper case roman storage locations wasn't working due to a minor typo. Fixed in this version (only affects Windows & Linux builds).

v1.30 - Material Densities

Added a set of common material densities (all measured in kg/m³) to the page of scientific constants. These densities can be useful when (for example) estimating the mass of a part.

For example, imagine a 400 mm length of 60 mm diameter aluminium round bar. The area of a circle is πr², so the volume of the cylinder is πr²l, so the calculator can be used to calculate the volume as approximately 1,130,973 mm³. The conversion button "m³←" converts this to 0.001131 m³ and multiplying this by the density of aluminium (2700 kg/m³) gives the expected mass of 3.05 kg.

The android version has also been updated; this can be downloaded from https://rpn.cgtk.co.uk/android/latest.html

v1.2.0 Version checking

Added the ability to check for the availability of newer versions.

v1.1.0 - Trigonometry bug-fix

Due to a brain-dead search & replace modification, a stupid trigonometry bug crept into the first public release.

This release fixes that bug.