Fixed a typo in iedropone.sthlp and suggested some changes in notations in iebaltab.ado

[mizuhirosuzuki]

I prefer to use italic letters for t-test, p-value, and F-test (like $t$-value in latex), but this is just my preference. But I think "T-test" in iebaltab needs to be "t-test" at least.

[kbjarkefur]

@luizaandrade I will let you handle this as you are in the middle of a big re-write of iebaltab.

[kbjarkefur]

iebaltab had progressed so much it had too gnarly conflicts so I moved the typo fixes in the other two files to 139177fdf2094fcfd1549d904b6050d343d890f3 and 766a7e92e804126804a9a45dd71f20ea48fdd572