VP and forth-wordlist as pvalues

[mkobetic]

We don't want DP to be a PVALUE because it updates too frequently during compilation, it could swamp the pvarena. Instead we will determine dp.flash by searching for the first erased area after forth-wordlist, with the exception that if forth-wordlist < dp0.flash we'll leave dp.flash set to the initial value (we don't want to go lower than dp0 accidentally).

• adds init.dp.flash that searches for free space after FORTH_WORDLIST to initialize dp.flash
• adds init.dp.flash to warm to set dp.flash during boot (must be after pv.init and first-boot-done)
• changes pv.store to take RAM address instead of XT to make it suitable as a VALUE setter for pvalues
• changes VP and FORTH_WORDLIST to be pvalues
• changes ENDDICT macro to put FORTH_WORDLIST last (core-wordlist was missing from the dictionary)
• fixes RA4 2!i to preserve flash.cache (as ~!i does)
• fixes RV naligned, adds tests
• fixes dallot next page erasing to check if we're crossing into the new page not just hitting its start address
• renames some symbols for readability
• some ITC code reformatting and commenting to help with understanding
• reformats all THROWs to have the code on the same line, so that it's easier to find where a given exception is thrown by searching for XT_THROW