expr: trying to fix expr parsing, sub decl, and sub calls
p2: parse block as stmt, fixes tests base/block.pl and method call numbers/chr.pl
p2: load "string" for p2

handle general case for load as method on string.
test p2 interactive, e.g. -e""

Fixed conflicts:
	front/p2.c
p2 syn: more expr and sub/method call changes.

There is still a msg tuple too much at the beginning
add PN_TUPIF
fix call and expressions (TUP)

calls and assignments and expressions now look like potion wants it
variable consume the next space, more expr fixes
p5_sig: get from P->source, not $$
p2 call: move 1st argument ufront, then opt. the rest
fix call and expressions (TUP)

calls and assignments and expressions now look like potion wants it

Fixed conflicts:
	syn/syntax-p5.y
p2 call: move 1st argument ufront, then opt. the rest
expr: minor expr syntax adjustment (still failing)

fixes simple expressions, like test/numbers/add.pl
syn: put -DP lexer rules together, revamp expr into opexpr and (call)expr
expr: fix opexpr, fixed parens.pl

-Dc compile prints now the sub tree
expr always requires a tuple
--value and value++ only act upon mvalue (variable or immediate)
-Dc list (expr %s) => %s
expr: fix simple p2 calls
expr: listexprs sep by comma, calllist special case, list assignment
fix example/fib.pn

return correct result. it is also a bit faster now
fix -DP combinations with other Potion flags

p2 has G->debug always enabled
travis: init libuv for p2