tests/hgterm.ti

bundle: move file chunk generation to it's own function

Moves the file chunk generation part of bundle creation to it's own function.
This allows extensions to customize the filelog part of bundle generation.

hgterm,
	am, km, mir, msgr, xenl,
	colors#8, cols#80, it#8, lines#24, pairs#64,
	acsc=``aaffggiijjkkllmmnnooppqqrrssttuuvvwwxxyyzz{{||}}~~,
	bel=^G, bold=\E[1m, clear=\E[H\E[2J, cr=\r,
	csr=\E[%i%p1%d;%p2%dr, cub=\E[%p1%dD, cub1=\b,
	cud=\E[%p1%dB, cud1=\n, cuf=\E[%p1%dC, cuf1=\E[C,
	cup=\E[%i%p1%d;%p2%dH, cuu=\E[%p1%dA, cuu1=\E[A,
	dch=\E[%p1%dP, dch1=\E[P, dl=\E[%p1%dM, dl1=\E[M,
	ed=\E[J, el=\E[K, enacs=\E)0, home=\E[H, ht=\t,
	hts=\EH, il=\E[%p1%dL, il1=\E[L, ind=\n,
	is2=\E[m\E[?7h\E[4l\E>\E7\E[r\E[?1;3;4;6l\E8, kbs=\b,
	kcub1=\EOD, kcud1=\EOB, kcuf1=\EOC, kcuu1=\EOA,
	kdch1=\E[3~, kf1=\E[11~, kf10=\E[21~, kf11=\E[23~,
	kf12=\E[24~, kf13=\E[25~, kf14=\E[26~, kf15=\E[28~,
	kf16=\E[29~, kf17=\E[31~, kf18=\E[32~, kf19=\E[33~,
	kf2=\E[12~, kf20=\E[34~, kf3=\E[13~, kf4=\E[14~,
	kf5=\E[15~, kf6=\E[17~, kf7=\E[18~, kf8=\E[19~,
	kf9=\E[20~, kfnd=\E[1~, kich1=\E[2~, kmous=\E[M,
	knp=\E[6~, kpp=\E[5~, kslt=\E[4~, op=\E[m, rc=\E8,
	rev=\E[7m, ri=\EM, rmacs=^O, rmcup=\E[2J\E[?47l\E8,
	rmir=\E[4l, rmkx=\E[?1l\E>, rmso=\E[m, rmul=\E[m,
	rs2=\E[m\E[?7h\E[4l\E>\E7\E[r\E[?1;3;4;6l\E8, sc=\E7,
	setab=\E[4%p1%dm, setaf=\E[3%p1%dm, sgr0=\E[m,
	smacs=^N, smcup=\E7\E[?47h, smir=\E[4h,
	smkx=\E[?1h\E=, smso=\E[7m, smul=\E[4m, tbc=\E[3g,
	u6=\E[%i%d;%dR, u7=\E[6n, u8=\E[?1;2c, u9=\E[c,