Preparations for adding	new functions:
 * Reassign LIN to ID=42
 * Rename SIN to SINF
Adding FUN TURN
Added unary operator FUNs: SIN COS LOG LOG10 EXP. They where tested by writing the same expression in different ways (SQRT = POW t 0.5 etc) or inverse functions (t = LOG EXP t etc).
Fix bug which led to incorrect function names in dynksets.dat
Added FUN LINSEG, reducing boilerplate code in dynk_parseFUN by introducing subroutine dynk_checkargs(nfields,nfields_expected,funsyntax) and subroutine dynk_checkspace(iblocks,fblocks,cblocks)
Added NOFILE flag for DYNK
Remove restriction for negative effective turn numbers
Added FUN QUAD and QUADSEG
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